重新选择时清除级联组合框

Question

我正在创建一个使用多个 ComboBox 的 excel 用户表单。第一个 ComboBox 列出了表格第 1 列中的值，下面的 ComboBox' 列出了以下列中的值。从 ComboBox 2 开始，也只根据前面的框列出值。所有 ComboBox' 仅显示唯一值。

这是我正在使用的当前代码：

Option Explicit
Private Sub ComboBox1_Change()
    Call cValues(ComboBox1.Value, ComboBox2, 2)
End Sub
Private Sub ComboBox2_Change()
    Call cValues(ComboBox2.Value, ComboBox3, 3)
End Sub
Private Sub ComboBox3_Change()
    Call cValues(ComboBox3.Value, ComboBox4, 4)
End Sub
Private Sub ComboBox4_Change()
    Call cValues(ComboBox4.Value, ComboBox5, 5)
End Sub
Private Sub ComboBox5_Change()
    Call cValues(ComboBox5.Value, ComboBox6, 6)
End Sub

Private Sub UserForm_Initialize()
    Dim Rng         As Range
    Dim Dn          As Range
    Dim Dic         As Object
    With Sheets("Listuni")
        Set Rng = .Range(.Range("A2"), .Range("A" & Rows.Count).End(xlUp))
    End With
    Set Dic = CreateObject("scripting.dictionary")
    Dic.CompareMode = vbTextCompare

    For Each Dn In Rng: Dic(Dn.Value) = Empty: Next
    Me.ComboBox1.List = Application.Transpose(Dic.keys)
End Sub

Sub cValues(txt As String, Obj As Object, col As Integer)
    Dim Dn              As Range
    Dim Rng             As Range
    Dim Dic             As Object
    With Sheets("Listuni")
        Set Rng = .Range(.Cells(2, col), .Cells(Rows.Count, col).End(xlUp))
    End With
    Set Dic = CreateObject("Scripting.Dictionary")
    Dic.CompareMode = 1

    For Each Dn In Rng
        If Dn.Offset(, -1).Value = txt Then
            If Not Dic.exists(Dn.Value) Then
                Dic(Dn.Value) = Empty
            End If
        End If
    Next Dn
    Obj.List = Application.Transpose(Dic.keys)
End Sub

当用户重新选择前面的 ComboBox 时，会出现我遇到的问题。不会清除后续框，而是保留所有现有选择。

每次重新选择前面的 ComboBox 时，我都在寻找一种方法来清除/默认后续 ComboBox 的值。例如，如果我在 ComboBox 1 和 2 中进行了选择，然后在 ComboBox 1 中更改了我的选择，我希望 ComboBox 2 清除而不是显示我之前的选择。请注意，用户表单在启动时的默认位置在任何 ComboBox 中都没有显示任何值。

我曾尝试使用 .clear 方法进行更改，但这总是挂在：

Obj.List = Application.Transpose(Dic.keys) 

我怀疑这是因为清除在技术上是一种更改，因此它不能根据空值将值列表转置到其他框。

Answer 1

这会清除所有后续的 ComboBox - 如果 Combo1 更改，则清除 Combo2、3、4、5 和 6

Option Explicit

Private ws  As Worksheet
Private d   As Object

Private Sub UserForm_Initialize()
    Dim cel As Range, txt As String, rng As Range

    Set ws = Worksheets("Listuni")
    Set d = CreateObject("Scripting.Dictionary"): d.CompareMode = vbTextCompare

    Set rng = ws.Range(ws.Cells(2, 1), ws.Cells(ws.Rows.Count, 1).End(xlUp))

    For Each cel In rng: d(cel.Value) = Empty: Next
    ComboBox1.List = Application.Transpose(d.keys)
End Sub

Private Function setList(ByVal txt As String, ByRef cmb As ComboBox) As Object
    Dim xID As Long, rng As Range, cel As Range, x As Control

    xID = Right(cmb.Name, 1)
    For Each x In Me.Controls
        If TypeName(x) = "ComboBox" Then If Val(Right(x.Name, 1)) > xID - 1 Then x.Clear
    Next

    Set rng = ws.Range(ws.Cells(2, xID), ws.Cells(ws.Rows.Count, xID).End(xlUp))

    d.RemoveAll
    For Each cel In rng
        If cel.Offset(, -1) = txt Then
            If Not d.exists(cel.Value) Then
                d(cel.Value) = Empty
            End If
        End If
    Next
    If d.Count > 0 Then cmb.List = Application.Transpose(d.keys) Else cmb.Clear
End Function

Private Sub ComboBox1_Change()
    setList ComboBox1.Value, ComboBox2
End Sub
Private Sub ComboBox2_Change()
    setList ComboBox2.Value, ComboBox3
End Sub
Private Sub ComboBox3_Change()
    setList ComboBox3.Value, ComboBox4
End Sub
Private Sub ComboBox4_Change()
    setList ComboBox4.Value, ComboBox5
End Sub
Private Sub ComboBox5_Change()
    setList ComboBox5.Value, ComboBox6
End Sub

---