算法：

1.将姓名都装入一个数组，并记录下需随机的数a，首次为数组长度
2.随机产生0~a的一个整数i
3.输出数组arr(i)，同时将最末尾的arr(a)放到arr(i)位置，并且a-1
4.再次点击窗体，开始重复执行3

 解释：总体思想就是每次只对未参与随机的元素进行随机。上面的算法也可以倒过来，把随机过的数值前置，从每次随机：0~5、0~4、0~3 。。。 变为每次随机：0~5、1~5、2~5 。。。 有人会问如果随机过的索引都在那个区间不就重复了吗？看算法，每次随机后都已经将它“拎出去了”

 代码实现：

Option Explicit
Dim arr
Dim a As Integer
'初始化
Private Sub Form_Load()
    arr = Split("A001,A002,A003,A004,A005,A006", ",")
    a = UBound(arr)
End Sub
'点一次，随机一个出来
Private Sub Command1_Click()
    Dim i As Integer, intRnd As Integer, strTmp As String
    
    If a = -1 Then
        MsgBox "所有成员都随机过一次了！", vbExclamation
        Exit Sub
    End If
    
    Randomize
    intRnd = Int(Rnd * a)
    
    Me.Print "索引:" & intRnd, arr(intRnd), "提取前:" & Join(arr, ",") & " 参与随机" & a + 1 & "个", '输出并写入文件
    Open "结果.txt" For Append As #1
    Print #1, arr(intRnd)
    Close #1
    
    strTmp = arr(intRnd)
    arr(intRnd) = arr(a)
    arr(a) = strTmp
    a = a - 1
    Me.Print "提取后:" & Join(arr, ",") & " 剩余" & a + 1 & "个"
End Sub

运行结果：

更新的优化版本：

Option Explicit

Dim arrStudentName '存放学生姓名的数组，将会在下面初始化
Dim intLastCursor As Integer '始终记录需参与随机数组的最后一个索引。比如第一次在0~5随机，下次在0~4随机。。。
'初始化
Private Sub Form_Load()
    Me.AutoRedraw = True
    arrStudentName = Split("A001,A002,A003,A004,A005,A006", ",")
    intLastCursor = UBound(arrStudentName)
End Sub
'点一次，随机一个出来
Private Sub Form_Click()
    Dim i As Integer, intRnd As Integer
    
    If intLastCursor = -1 Then MsgBox "所有成员都随机过一次了！", vbExclamation: Exit Sub
    
    Randomize
    intRnd = Int(Rnd * intLastCursor)
    Me.Print "索引:" & intRnd, arrStudentName(intRnd), "提取前数组打印:" & Join(arrStudentName, ",") & " 参与随机" & intLastCursor + 1 & "个", '输出并写入文件
    
    arrStudentName(intRnd) = arrStudentName(intLastCursor) '将数组最末的数字“提”到已经随机出去的“位置”
    intLastCursor = intLastCursor - 1 '参与随机的数字-1，第二次只在0~4随机，在下一次在0~3随机，以此类推
    Me.Print "提取后数组打印:" & Join(arrStudentName, ",") & " 剩余" & intLastCursor + 1 & "个"
End Sub

继续简化版本：

Option Explicit
Dim arr1, intStartIndex As Integer, intRnd As Integer
Private Sub Form_Load()
    arr1 = Array("a", "b", "c", "d", "e", "f", "g", "h", "i", "j") '初始化
    intLastIndex = UBound(arr1)
End Sub
Private Sub Form_Click()
    If intStartIndex > UBound(arr1) Then MsgBox "都已经随机完了!", vbExclamation: Exit Sub
    Randomize '随机数生成器初始化
    intRnd = Int(Rnd * intLastIndex) '随机产生数字介于：0~intLastIndex
    Print intLastIndex, arr1(intRnd)
    arr1(intRnd) = arr1(intLastIndex)
    intLastIndex = intLastIndex - 1
End Sub

前置的版本：

Option Explicit
Dim arr1, intStartIndex As Integer, intRnd As Integer
Private Sub Form_Load()
    arr1 = Array("a", "b", "c", "d", "e", "f", "g", "h", "i", "j") '初始化
End Sub
Private Sub Form_Click()
    If intStartIndex > UBound(arr1) Then MsgBox "都已经随机完了!", vbExclamation: Exit Sub
    Randomize '随机数生成器初始化
    intRnd = intStartIndex + Int(Rnd * (UBound(arr1) - intStartIndex)) '随机产生数字介于：intStartIndex~数组最大索引
    Print intStartIndex, arr1(intRnd)
    arr1(intRnd) = arr1(intStartIndex)
    intStartIndex = intStartIndex + 1
End Sub