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我正在尝试遍历窗体上的控件以显示那些支持 ControlSource 的控件的 ControlSource 属性。

我发现识别具有 ControlSource 属性的控件相对容易。问题在于访问这些控件的属性。通用 Control 对象没有 ControlSource 属性。如果我使用另一种语言，我只需将作为列表框的控件强制转换为 ListBox 对象，例如，访问 ControlSource 属性。但我的理解是，在 VBA 中没有类型继承，所以我不能将一种类型的对象转换为另一种类型的对象。

那么如何访问那些支持该属性的控件的 ControlSource 属性呢？

到目前为止，这是我的代码：

Private Sub IterateControlsOnForm()
Dim frm As Form, formName As String
' The only controls that have a ControlSource property are either
'   BoundObjectFrame controls or ListBox controls.
Dim ctrl As Control
Dim boundObjectFrame As boundObjectFrame, listBoxCtrl As listBox
Dim boundObjectFrameTypes() As String, listBoxTypes() As String
Dim ctrlType As String

    formName = "MAINFORM"

    ' Useful way of populating a string array - use Split function.
    '   Array function only works with Variants.
    boundObjectFrameTypes = _
        Split("CheckBox,ComboBox,CustomControl,GroupLevel", ",")
    listBoxTypes = Split("OptionButton,OptionGroup,TextBox,TextBox", ",")

    ' Assumes form is open.
    Set frm = Forms(formName)
    For Each ctrl In frm.Controls
        ' Ignore controls that do not have a ControlSource property.
        ctrlType = TypeName(ctrl)
        If IsStringInArray(ctrlType, boundObjectFrameTypes) Then
            ' **** FOLLOWING LINE FAILS ****
            Set boundObjectFrame = ctrl
            Debug.Print boundObjectFrame.Name & "(" & ctrlType & ") " & _
                "ControlSource Property: " & boundObjectFrame.ControlSource
        ElseIf IsStringInArray(ctrlType, listBoxTypes) Then
            ' **** FOLLOWING LINE FAILS ****
            Set listBoxCtrl = frm.Controls(ctrl.Name)
            Debug.Print listBoxCtrl.Name & "(" & ctrlType & ") " & _
                "ControlSource Property: " & listBoxCtrl.ControlSource
        End If
    Next ctrl
End Sub

我尝试了两种将通用 Control 对象转换为具有 ControlSource 属性的更具体控件的方法。请参阅两条评论“ ** FOLLOWING LINE FAILS ** ”。

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1 回答 1

2

使用对象怎么样？

Private Sub IterateControlsOnForm()
Dim frm As Form, formName As String
' The only controls that have a ControlSource property are either
'   BoundObjectFrame controls or ListBox controls.
Dim ctrl As Control
Dim boundObjectFrame As Object, listBoxCtrl As Object
Dim boundObjectFrameTypes As String, listBoxTypes As String
Dim ctrlType As String

    formName = "MAINFORM"

    ' Useful way of populating a string array - use Split function.
    '   Array function only works with Variants.
    boundObjectFrameTypes = _
        ",CheckBox,ComboBox,CustomControl,GroupLevel"
    listBoxTypes = ",OptionButton,OptionGroup,TextBox,TextBox"

    ' Assumes form is open.
    Set frm = Forms(formName)
    For Each ctrl In frm.Controls
        ' Ignore controls that do not have a ControlSource property.
        ctrlType = TypeName(ctrl)
        If InStr(boundObjectFrameTypes, "," & ctrlType) Then
            Set boundObjectFrame = ctrl
            Debug.Print boundObjectFrame.Name & "(" & ctrlType & ") " & _
                "ControlSource Property: " & boundObjectFrame.ControlSource
        ElseIf InStr(listBoxTypes, "," & ctrlType) Then
            Set listBoxCtrl = frm.Controls(ctrl.Name)
            Debug.Print listBoxCtrl.Name & "(" & ctrlType & ") " & _
                "ControlSource Property: " & listBoxCtrl.ControlSource
        End If
    Next ctrl
End Sub

使用 VBA，您还可以使用 On Error Resume Next，尽管我同意通常最好避免错误。

formName = "MAINFORM"

Set frm = Forms(formName)
For Each ctrl In frm.Controls
On Error Resume Next
    Debug.Print ctrl.Name _
        & " ControlSource Property: " & ctrl.ControlSource
    If Err.Number = 438 Then
        Err.Clear
    End If
Next
于 2012-10-25T22:22:35.410 回答