Question

我试图枚举满足特定条件的表单中的所有控件，如代码beelow

Public Enum MethodSeachEnum
    StartsWith = 1
    EndsWith = 2
    Contains = 3
End Enum

Public Function GetAllControls(Control As Control, Key As String, MethodSeach As MethodSeachEnum, ControlType As Type, Optional UseTag As Boolean = True) As IEnumerable(Of Control)
    Dim controls = Control.Controls.Cast(Of Control)()

    Return (controls.SelectMany(Function(ctrl) GetAllControls(ctrl, Metodo)).Concat(controls).Where(Function(c)
            Select Case MethodSeach
                Case MetodoSeachEnum.EndsWith
                    If (UseTag) Then
                        Return c.Tag.ToString.ToUpper.EndsWith(Key.ToUpper) And c.GetType() Is ControlType 
                    Else
                        Return c.Name.ToUpper.EndsWith(Key.ToUpper) And c.GetType() Is ControlType 
                    End If
                Case MetodoSeachEnum.StartsWith
                    If (UseTag) Then
                        Return c.Tag.ToString.ToUpper.StartsWith(Key.ToUpper) And c.GetType() Is ControlType 
                    Else
                        Return c.Name.ToUpper.StartsWith(Key.ToUpper) And c.GetType() Is ControlType 
                    End If
                Case MetodoSeachEnum.Contains
                    If (UseTag) Then
                        Return c.Tag.ToString.ToUpper.Contains(Key.ToUpper) And c.GetType() Is ControlType 
                    Else
                        Return c.Name.ToUpper.Contains(Key.ToUpper) And c.GetType() Is ControlType 
                    End If
                Case Else
                    Return False
            End Select
        End Function))
End Function

在我的表单中有一个GroupBox，里面有一些TextBox。这些TextBox不会被退回，我也不明白为什么......

这是我如何调用此函数

Dim ctrls = GetAllControls(FormTagliente, "txtQuote", MetodoSeachEnum.StartsWith, GetType(TextBox), False)

        For Each txt As TextBox In ctrls 

            ...

        Next

Answer 1

恕我直言的信息太少，无法回答你的问题“为什么这对你的具体情况不起作用” 你的代码中也缺少带有两个参数的GetAllControls，也许问题在于无论如何，我玩了一些你的代码（但没有测试它，所以它更像是POC），这就是我得到的：

$oid

我们的想法是将“构造标准逻辑”与实际的“循环，搜索，产生”分开，使用通用约束强制targetType为Control（并直接使用“good”返回类型）。我也发现使用Enum SearchMethod StartsWith = 1 EndsWith = 2 Contains = 3 End Enum Function GetAllControls(Of T As Control)(ctrl As Control, key As String, method As SearchMethod, Optional useTag As Boolean = True) As IEnumerable(Of T) ' TODO validate args Dim upperKey = key.ToUpper Dim searchPredicates() As Func(Of String, Boolean) = { Function(src, tgt) src.StartsWith(upperKey), Function(src, tgt) src.EndsWith(upperKey), Function(src, tgt) src.Contains(upperKey) } Dim ctrlSelector As Func(Of Control, String) = If(useTag, Function(c) c.Tag.ToString.ToUpper, Function(c) c.Name.ToUpper) Return GetAllControlsIterator(Of T)(ctrl, ctrlSelector, searchPredicates(CInt(method) - 1)) End Function Private Iterator Function GetAllControlsIterator(Of T As Control)(ctrl As Control, ctrlSelector As Func(Of Control, String), searchPredicate As Func(Of String, Boolean)) As IEnumerable(Of T) For Each child In ctrl.Controls If searchPredicate(ctrlSelector(child)) AndAlso TypeOf child Is T Then Yield DirectCast(child, T) For Each grandChild In GetAllControlsIterator(Of T)(child, ctrlSelector, searchPredicate) Yield DirectCast(grandChild, T) Next Next End Function块更简单，但更个性化也许这可以帮助你解决问题？

枚举表单中的所有控件（冗余）

1 个答案: