获取本机缓存

<view class="iconItem" @click="clern">
	<view class="register">
		<u-icon color='#EBB24C' name="trash"></u-icon>清除缓存
	</view>
	<view class="iconJt phone">
		{
    {
    fileSizeString}}
	</view>
</view>

			// 获取缓存
			formatSize() {
    
				let that = this;
				plus.cache.calculate(function(size) {
    
					let sizeCache = parseInt(size);
					if (sizeCache == 0) {
    
						that.fileSizeString = "0B";
					} else if (sizeCache < 1024) {
    
						that.fileSizeString = sizeCache + "B";
					} else if (sizeCache < 1048576) {
    
						that.fileSizeString = (sizeCache / 1024).toFixed(2) + "KB";
					} else if (sizeCache < 1073741824) {
    
						that.fileSizeString = (sizeCache / 1048576).toFixed(2) + "MB";
					} else {
    
						that.fileSizeString = (sizeCache / 1073741824).toFixed(2) + "GB";
					}
				});
			},
			// 清除缓存
			clern() {
    
				let that = this
				uni.showModal({
    
					title: '清除缓存',
					content: '您确定要清除缓存吗？',
					success: function(res) {
    
						if (res.confirm) {
    
							console.log('用户点击确定');
							that.clearCache()
							// uni.clearStorage();
							uni.navigateTo({
    
								url: '../../login/loginW'
							})
						} else if (res.cancel) {
    
							console.log('用户点击取消');
						}
					}
				});
			},
			// 清理缓存
			clearCache() {
    
				let that = this;
				let os = plus.os.name;
				if (os == 'Android') {
    
					let main = plus.android.runtimeMainActivity();
					let sdRoot = main.getCacheDir();
					let files = plus.android.invoke(sdRoot, "listFiles");
					let len = files.length;
					for (let i = 0; i < len; i++) {
    
						let filePath = '' + files[i]; // 没有找到合适的方法获取路径，这样写可以转成文件路径  
						plus.io.resolveLocalFileSystemURL(filePath, function(entry) {
    
							if (entry.isDirectory) {
    
								entry.removeRecursively(function(entry) {
     //递归删除其下的所有文件及子目录  
									uni.showToast({
    
										title: '缓存清理完成',
										duration: 2000
									});
									that.formatSize(); // 重新计算缓存  
								}, function(e) {
    
									console.log(e.message)
								});
							} else {
    
								entry.remove();
							}
						}, function(e) {
    
							console.log('文件路径读取失败')
						});
					}
				} else {
     // ios  
					plus.cache.clear(function() {
    
						uni.showToast({
    
							title: '缓存清理完成',
							duration: 2000
						});
						that.formatSize();
					});
				}
			},