黑马程序员Android 百分比布局库(percent-support-lib) 解析与扩展_黑马教育百分比布局素材包-程序员宅基地
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一、概述
周末游戏打得过猛，于是周天熬夜码代码，周一早上浑浑噩噩的发现android-percent-support-lib-sample这个项目，Google终于开始支持百分比的方式布局了，瞬间脉动回来，啊咧咧。对于这种历史性的时刻，不出篇博客难以表达我内心的激动。
还记得不久前，发了篇博客：Android 屏幕适配方案，这篇博客以Web页面设计引出一种适配方案，最终的目的就是可以通过百分比控制控件的大小。当然了，存在一些问题，比如：
- 对于没有考虑到屏幕尺寸，可能会出现意外的情况；
- apk的大小会增加；
当然了android-percent-support这个库，基本可以解决上述问题，是不是有点小激动，稍等，我们先描述下这个support-lib。
这个库提供了：
-
两种布局供大家使用：
PercentRelativeLayout、PercentFrameLayout，通过名字就可以看出，这是继承自FrameLayout和RelativeLayout两个容器类； -
支持的属性有：
layout_widthPercent、layout_heightPercent、
layout_marginPercent、layout_marginLeftPercent、
layout_marginTopPercent、layout_marginRightPercent、
layout_marginBottomPercent、layout_marginStartPercent、layout_marginEndPercent。
可以看到支持宽高，以及margin。
也就是说，大家只要在开发过程中使用PercentRelativeLayout、PercentFrameLayout替换FrameLayout、RelativeLayout即可。
是不是很简单，不过貌似没有LinearLayout，有人会说LinearLayout有weight属性呀。但是，weight属性只能支持一个方向呀~~哈，没事，刚好给我们一个机会去自定义一个PercentLinearLayout。
好了，本文分为3个部分：
PercentRelativeLayout、PercentFrameLayout的使用- 对上述控件源码分析
- 自定义
PercentLinearLayout
二、使用
关于使用，其实及其简单，并且github上也有例子，android-percent-support-lib-sample。我们就简单过一下：
首先记得在build.gradle添加：
<code class="language-xml hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> compile 'com.android.support:percent:22.2.0'</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>
（一）PercentFrameLayout
<code class="language-xml hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-pi" style="color: rgb(0, 102, 102); box-sizing: border-box;"><?xml version="1.0" encoding="utf-8"?></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">android.support.percent.PercentFrameLayout
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:android</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res/android"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:app</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res-auto"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"left|top"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#44ff0000"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:30%,height:20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"30%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"right|top"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#4400ff00"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:70%,height:20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"70%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"bottom"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#770000ff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:100%,height:10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"100%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">android.support.percent.PercentFrameLayout</span>></span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li></ul>
3个TextView，很简单，直接看效果图：
(二) PercentRelativeLayout
<code class="language-xml hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-pi" style="color: rgb(0, 102, 102); box-sizing: border-box;"><?xml version="1.0" encoding="utf-8"?></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">android.support.percent.PercentRelativeLayout
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:android</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res/android"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:app</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res-auto"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:clickable</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"true"</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:id</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@+id/row_one_item_one"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_alignParentTop</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"true"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#7700ff00"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"w:70%,h:20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"70%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:id</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@+id/row_one_item_two"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_toRightOf</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@+id/row_one_item_one"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#396190"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"w:30%,h:20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"30%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">ImageView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:id</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@+id/row_two_item_one"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:src</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@drawable/tangyan"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:scaleType</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"centerCrop"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_below</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@+id/row_one_item_one"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#d89695"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"70%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_below</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@id/row_two_item_one"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#770000ff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:100%,height:10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"100%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">android.support.percent.PercentRelativeLayout</span>></span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li></ul>
ok，依然是直接看效果图:
使用没什么好说的，就是直观的看一下。
三、源码分析
其实细想一下，Google只是对我们原本熟悉的RelativeLayout和FrameLayout进行的功能的扩展，使其支持了percent相关的属性。
那么，我们考虑下，如果是我们添加这种扩展，我们会怎么做：
- 通过LayoutParams获取child设置的percent相关属性的值
- onMeasure的时候，将child的width,height的值，通过获取的自定义属性的值进行计算（eg:容器的宽 * fraction ），计算后传入给child.measure(w,h);
ok，有了上面的猜想，我们直接看PercentFrameLayout的源码。
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentFrameLayout</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">extends</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">FrameLayout</span> {</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> PercentLayoutHelper mHelper = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutHelper(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//省略了，两个构造方法</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">PercentFrameLayout</span>(Context context, AttributeSet attrs) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(context, attrs);
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> LayoutParams <span class="hljs-title" style="box-sizing: border-box;">generateLayoutParams</span>(AttributeSet attrs) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> LayoutParams(getContext(), attrs);
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onMeasure</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthMeasureSpec, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightMeasureSpec) {
mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mHelper.handleMeasuredStateTooSmall()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onLayout</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> changed, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> left, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> top, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> right, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> bottom) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onLayout(changed, left, top, right, bottom);
mHelper.restoreOriginalParams();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">LayoutParams</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">extends</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">FrameLayout</span>.<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">LayoutParams</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">implements</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentLayoutHelper</span>.<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentLayoutParams</span> {</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">LayoutParams</span>(Context c, AttributeSet attrs) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(c, attrs);
mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//省略了一些代码...</span>
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> PercentLayoutHelper.PercentLayoutInfo <span class="hljs-title" style="box-sizing: border-box;">getPercentLayoutInfo</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mPercentLayoutInfo;
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setBaseAttributes</span>(TypedArray a, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthAttr, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightAttr) {
PercentLayoutHelper.fetchWidthAndHeight(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>, a, widthAttr, heightAttr);
}
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li></ul>
代码是相当的短，可以看到PercentFrameLayout里面首先重写了generateLayoutParams方法，当然了，由于支持了一些新的layout_属性，那么肯定需要定义对应的LayoutParams。
（一）percent相关属性的获取
可以看到PercentFrameLayout.LayoutParams在原有的FrameLayout.LayoutParams基础上，实现了PercentLayoutHelper.PercentLayoutParams接口。
这个接口很简单，只有一个方法：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">interface</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentLayoutParams</span> {</span>
PercentLayoutInfo getPercentLayoutInfo();
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
而，这个方法的实现呢，也只有一行：return mPercentLayoutInfo;，那么这个mPercentLayoutInfo在哪完成赋值呢？
看PercentFrameLayout.LayoutParams的构造方法：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">LayoutParams</span>(Context c, AttributeSet attrs) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(c, attrs);
mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
可以看到，将attrs传入给getPercentLayoutInfo方法，那么不用说，这个方法的内部，肯定是获取自定义属性的值，然后将其封装到PercentLayoutInfo对象中，最后返回。
代码如下：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> PercentLayoutInfo <span class="hljs-title" style="box-sizing: border-box;">getPercentLayoutInfo</span>(Context context,
AttributeSet attrs) {
PercentLayoutInfo info = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.PercentLayout_Layout);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> value = array.getFraction(R.styleable.PercentLayout_Layout_layout_widthPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent width: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.widthPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_heightPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent height: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.heightPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.leftMarginPercent = value;
info.topMarginPercent = value;
info.rightMarginPercent = value;
info.bottomMarginPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginLeftPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent left margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.leftMarginPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginTopPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent top margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.topMarginPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginRightPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent right margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.rightMarginPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginBottomPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent bottom margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.bottomMarginPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginStartPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent start margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.startMarginPercent = value;
}
value = array.getFraction(R.styleable.PercentLayout_Layout_layout_marginEndPercent, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>,
-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (value != -<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>f) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"percent end margin: "</span> + value);
}
info = info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? info : <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutInfo();
info.endMarginPercent = value;
}
array.recycle();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"constructed: "</span> + info);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> info;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li><li style="box-sizing: border-box; padding: 0px 5px;">81</li><li style="box-sizing: border-box; padding: 0px 5px;">82</li><li style="box-sizing: border-box; padding: 0px 5px;">83</li><li style="box-sizing: border-box; padding: 0px 5px;">84</li><li style="box-sizing: border-box; padding: 0px 5px;">85</li><li style="box-sizing: border-box; padding: 0px 5px;">86</li><li style="box-sizing: border-box; padding: 0px 5px;">87</li><li style="box-sizing: border-box; padding: 0px 5px;">88</li><li style="box-sizing: border-box; padding: 0px 5px;">89</li><li style="box-sizing: border-box; padding: 0px 5px;">90</li><li style="box-sizing: border-box; padding: 0px 5px;">91</li><li style="box-sizing: border-box; padding: 0px 5px;">92</li></ul>
是不是和我们平时的取值很类似，所有的值最终封装到PercentLayoutInfo对象中。
ok，到此我们的属性获取就介绍完成，有了这些属性，是不是onMeasure里面要进行使用呢？
(二) onMeasue中重新计算child的尺寸
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onMeasure</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthMeasureSpec, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightMeasureSpec) {
mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mHelper.handleMeasuredStateTooSmall()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>
可以看到onMeasure中的代码页很少，看来核心的代码都被封装在mHelper的方法中，我们直接看mHelper.adjustChildren方法。
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Iterates over children and changes their width and height to one calculated from percentage
* values.
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> widthMeasureSpec Width MeasureSpec of the parent ViewGroup.
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> heightMeasureSpec Height MeasureSpec of the parent ViewGroup.
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">adjustChildren</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthMeasureSpec, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightMeasureSpec) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//...</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthHint = View.MeasureSpec.getSize(widthMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightHint = View.MeasureSpec.getSize(heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, N = mHost.getChildCount(); i < N; i++) {
View view = mHost.getChildAt(i);
ViewGroup.LayoutParams params = view.getLayoutParams();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (params <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> PercentLayoutParams) {
PercentLayoutInfo info =
((PercentLayoutParams) params).getPercentLayoutInfo();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"using "</span> + info);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (params <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> ViewGroup.MarginLayoutParams) {
info.fillMarginLayoutParams((ViewGroup.MarginLayoutParams) params,
widthHint, heightHint);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
info.fillLayoutParams(params, widthHint, heightHint);
}
}
}
}
}
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li></ul>
通过注释也能看出，此方法中遍历所有的孩子，通过百分比的属性重新设置其宽度和高度。
首先在widthHint、heightHint保存容器的宽、高，然后遍历所有的孩子，判断其LayoutParams是否是PercentLayoutParams类型，如果是，通过params.getPercentLayoutInfo拿出info对象。
是否还记得，上面的分析中，PercentLayoutInfo保存了percent相关属性的值。
如果info不为null，则判断是否需要处理margin；我们直接看fillLayoutParams方法（处理margin也是类似的）。
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Fills {@code ViewGroup.LayoutParams} dimensions based on percentage values.
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">fillLayoutParams</span>(ViewGroup.LayoutParams params, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthHint,
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightHint) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// Preserve the original layout params, so we can restore them after the measure step.</span>
mPreservedParams.width = params.width;
mPreservedParams.height = params.height;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (widthPercent >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {
params.width = (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>) (widthHint * widthPercent);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (heightPercent >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {
params.height = (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>) (heightHint * heightPercent);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"after fillLayoutParams: ("</span> + params.width + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">", "</span> + params.height + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">")"</span>);
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li></ul>
首先保存原本的width和height，然后重置params的width和height为(int) (widthHint * widthPercent)和(int) (heightHint * heightPercent);。
到此，其实我们的百分比转换就结束了，理论上就已经实现了对于百分比的支持，不过Google还考虑了一些细节。
我们回到onMeasure方法：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onMeasure</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthMeasureSpec, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightMeasureSpec) {
mHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mHelper.handleMeasuredStateTooSmall()) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>
下面还有个mHelper.handleMeasuredStateTooSmall的判断，也就是说，如果你设置的百分比，最终计算出来的MeasuredSize过小的话，会进行一些操作。
代码如下：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">handleMeasuredStateTooSmall</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> needsSecondMeasure = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, N = mHost.getChildCount(); i < N; i++) {
View view = mHost.getChildAt(i);
ViewGroup.LayoutParams params = view.getLayoutParams();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"should handle measured state too small "</span> + view + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" "</span> + params);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (params <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> PercentLayoutParams) {
PercentLayoutInfo info =
((PercentLayoutParams) params).getPercentLayoutInfo();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (shouldHandleMeasuredWidthTooSmall(view, info)) {
needsSecondMeasure = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
params.width = ViewGroup.LayoutParams.WRAP_CONTENT;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (shouldHandleMeasuredHeightTooSmall(view, info)) {
needsSecondMeasure = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
params.height = ViewGroup.LayoutParams.WRAP_CONTENT;
}
}
}
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"should trigger second measure pass: "</span> + needsSecondMeasure);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> needsSecondMeasure;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li></ul>
首先遍历所有的孩子，拿出孩子的layoutparams，如果是PercentLayoutParams实例，则取出info。如果info不为null，调用shouldHandleMeasuredWidthTooSmall判断：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">shouldHandleMeasuredWidthTooSmall</span>(View view, PercentLayoutInfo info) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> state = ViewCompat.getMeasuredWidthAndState(view) & ViewCompat.MEASURED_STATE_MASK;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> state == ViewCompat.MEASURED_STATE_TOO_SMALL && info.widthPercent >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> &&
info.mPreservedParams.width == ViewGroup.LayoutParams.WRAP_CONTENT;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>
这里就是判断，如果你设置的measuredWidth或者measureHeight过小的话，并且你在布局文件中layout_w/h 设置的是WRAP_CONTENT的话，将params.width / height= ViewGroup.LayoutParams.WRAP_CONTENT，然后重新测量。
哈，onMeasure终于结束了~~~现在我觉得应该代码结束了吧，尺寸都设置好了，还需要干嘛么，but，你会发现onLayout也重写了，我们又不改变layout规则，在onLayout里面干什么毛线：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onLayout</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> changed, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> left, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> top, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> right, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> bottom) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onLayout(changed, left, top, right, bottom);
mHelper.restoreOriginalParams();
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>
继续看mHelper.restoreOriginalParams
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Iterates over children and restores their original dimensions that were changed for
* percentage values. Calling this method only makes sense if you previously called
* {@link PercentLayoutHelper#adjustChildren(int, int)}.
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">restoreOriginalParams</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, N = mHost.getChildCount(); i < N; i++) {
View view = mHost.getChildAt(i);
ViewGroup.LayoutParams params = view.getLayoutParams();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"should restore "</span> + view + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" "</span> + params);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (params <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> PercentLayoutParams) {
PercentLayoutInfo info =
((PercentLayoutParams) params).getPercentLayoutInfo();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"using "</span> + info);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (info != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (params <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> ViewGroup.MarginLayoutParams) {
info.restoreMarginLayoutParams((ViewGroup.MarginLayoutParams) params);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
info.restoreLayoutParams(params);
}
}
}
}
}
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li></ul>
噗，原来是重新恢复原本的尺寸值，也就是说onMeasure里面的对值进行了改变，测量完成后。在这个地方，将值又恢复成如果布局文件中的值，上面写的都是0。恢复很简单：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">restoreLayoutParams</span>(ViewGroup.LayoutParams params) {
params.width = mPreservedParams.width;
params.height = mPreservedParams.height;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>
你应该没有忘在哪存的把~忘了的话，麻烦Ctrl+F ‘mPreservedParams.width’ 。
也就是说，你去打印上面写法，布局文件中view的v.getLayoutParams().width，这个值应该是0。
这里感觉略微不爽~这个0没撒用处呀，还不如不重置~~
好了，到此就分析完了，其实主要就几个步骤：
- LayoutParams中属性的获取
- onMeasure中，改变params.width为百分比计算结果，测量
- 如果测量值过小且设置的w/h是wrap_content，重新测量
- onLayout中，重置params.w/h为布局文件中编写的值
可以看到，有了RelativeLayout、FrameLayout的扩展，竟然没有LinearLayout几个意思。好在，我们的核心代码都由PercentLayoutHelper封装了，自己扩展下LinearLayout也不复杂。
三、实现PercentLinearlayout
可能有人会说，有了weight呀，但是weight能做到宽、高同时百分比赋值嘛？
好了，代码很简单，如下：
（一）PercentLinearLayout
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">package</span> com.juliengenoud.percentsamples;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.content.Context;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.content.res.TypedArray;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.support.percent.PercentLayoutHelper;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.util.AttributeSet;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.view.ViewGroup;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.widget.LinearLayout;
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Created by zhy on 15/6/30.
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentLinearLayout</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">extends</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">LinearLayout</span>
{</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> PercentLayoutHelper mPercentLayoutHelper;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">PercentLinearLayout</span>(Context context, AttributeSet attrs)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(context, attrs);
mPercentLayoutHelper = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> PercentLayoutHelper(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onMeasure</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthMeasureSpec, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightMeasureSpec)
{
mPercentLayoutHelper.adjustChildren(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mPercentLayoutHelper.handleMeasuredStateTooSmall())
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onLayout</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> changed, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> l, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> t, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> r, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> b)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onLayout(changed, l, t, r, b);
mPercentLayoutHelper.restoreOriginalParams();
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> LayoutParams <span class="hljs-title" style="box-sizing: border-box;">generateLayoutParams</span>(AttributeSet attrs)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> LayoutParams(getContext(), attrs);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">LayoutParams</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">extends</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">LinearLayout</span>.<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">LayoutParams</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">implements</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentLayoutHelper</span>.<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">PercentLayoutParams</span>
{</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> PercentLayoutHelper.PercentLayoutInfo mPercentLayoutInfo;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">LayoutParams</span>(Context c, AttributeSet attrs)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(c, attrs);
mPercentLayoutInfo = PercentLayoutHelper.getPercentLayoutInfo(c, attrs);
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> PercentLayoutHelper.PercentLayoutInfo <span class="hljs-title" style="box-sizing: border-box;">getPercentLayoutInfo</span>()
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mPercentLayoutInfo;
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setBaseAttributes</span>(TypedArray a, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> widthAttr, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> heightAttr)
{
PercentLayoutHelper.fetchWidthAndHeight(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>, a, widthAttr, heightAttr);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">LayoutParams</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> width, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> height) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(width, height);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">LayoutParams</span>(ViewGroup.LayoutParams source) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(source);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">LayoutParams</span>(MarginLayoutParams source) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(source);
}
}
}
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li><li style="box-sizing: border-box; padding: 0px 5px;">71</li><li style="box-sizing: border-box; padding: 0px 5px;">72</li><li style="box-sizing: border-box; padding: 0px 5px;">73</li><li style="box-sizing: border-box; padding: 0px 5px;">74</li><li style="box-sizing: border-box; padding: 0px 5px;">75</li><li style="box-sizing: border-box; padding: 0px 5px;">76</li><li style="box-sizing: border-box; padding: 0px 5px;">77</li><li style="box-sizing: border-box; padding: 0px 5px;">78</li><li style="box-sizing: border-box; padding: 0px 5px;">79</li><li style="box-sizing: border-box; padding: 0px 5px;">80</li><li style="box-sizing: border-box; padding: 0px 5px;">81</li><li style="box-sizing: border-box; padding: 0px 5px;">82</li><li style="box-sizing: border-box; padding: 0px 5px;">83</li><li style="box-sizing: border-box; padding: 0px 5px;">84</li><li style="box-sizing: border-box; padding: 0px 5px;">85</li><li style="box-sizing: border-box; padding: 0px 5px;">86</li><li style="box-sizing: border-box; padding: 0px 5px;">87</li><li style="box-sizing: border-box; padding: 0px 5px;">88</li><li style="box-sizing: border-box; padding: 0px 5px;">89</li><li style="box-sizing: border-box; padding: 0px 5px;">90</li><li style="box-sizing: border-box; padding: 0px 5px;">91</li></ul>
如果你详细看了上面的源码分析，这个代码是不是没撒解释的了~
（二）测试布局
<code class="language-xml hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-pi" style="color: rgb(0, 102, 102); box-sizing: border-box;"><?xml version="1.0" encoding="utf-8"?></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">com.juliengenoud.percentsamples.PercentLinearLayout
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:android</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res/android"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:app</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res-auto"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:orientation</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"vertical"</span>></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ff44aacc"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:60%,height:5%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:textColor</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ffffff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"5%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_marginBottomPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"5%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"60%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ff4400cc"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:textColor</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ffffff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:70%,height:10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_marginBottomPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"5%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"70%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ff44aacc"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:80%,height:15%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:textColor</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ffffff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"15%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_marginBottomPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"5%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"80%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ff4400cc"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:90%,height:5%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:textColor</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ffffff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"20%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_marginBottomPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"10%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_widthPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"90%"</span>/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">TextView
</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_width</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"match_parent"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:layout_height</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"0dp"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:background</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ff44aacc"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:gravity</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"center"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:text</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"width:100%,height:25%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:textColor</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"#ffffff"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_heightPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"25%"</span>
<span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">app:layout_marginBottomPercent</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"5%"</span>
/></span>
<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">com.juliengenoud.percentsamples.PercentLinearLayout</span>></span>
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li></ul>
我们纵向排列的几个TextView，分别设置宽/高都为百分比，且之间的间隔为5%p。
(三)效果图
ok，到此，我们使用、源码分析、扩展PercentLinearLayout就结束了。
添加PercentLinearLayout后的地址：点击查看
扩展下载:android-percent-support-extend 包含android studio, eclipse项目，以及上述源码。
~~have a nice day ~~
转载请标明出处：
http://blog.csdn.net/lmj623565791/article/details/46695347；
本文出自:【张鸿洋的博客】
版权声明：本文为博主原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接和本声明。
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