Question

我有一个动态网页，可以多次加载用户控件，包括根据需要多次加载用户控件。在用户控件中有四个控件：标题标签，转发器，占位符和Repeater内的AjaxControlToolkit评级控件。

结构可能如下所示：

Webpage
  Placeholder
    UserControl (repeater hidden, no data)
      Placeholder - [UserControl]
        UserControl
          Repeater
            RepeaterItem - [RatingControl]
            RepeaterItem - [RatingControl]
          Placeholder - [UserControl]
            UserControl (placeholder hidden, no data)
              Repeater
                RepeaterItem - [RatingControl]
                RepeaterItem - [RatingControl]
    UserControl
      Repeater
        RepeaterItem - [RatingControl]
        RepeaterItem - [RatingControl]
      Placeholder - [UserControl]
        UserControl (placeholder hidden, no data)          
          Repeater
            RepeaterItem - [RatingControl]

这是我的递归方法：

Protected Sub Get_Ratings(ByVal ctl As Control, ByVal grouptotal As Integer)
    If TypeOf ctl Is PerformanceEvaluationSubcontractorControl Then
        Dim pesctl As Control
        For Each pesctl In ctl.Controls
            If TypeOf pesctl Is PerformanceEvaluationSubcontractorControl Then
                Me.Get_Ratings(pesctl, grouptotal)
            ElseIf pesctl.Controls.Count > 0 Then
                Dim spesctl As Control
                For Each spesctl In pesctl.Controls
                    If TypeOf spesctl Is Repeater Then
                        Dim rptctl As Control
                        For Each rptctl In spesctl.Controls
                            Me.Get_Ratings(pesctl, grouptotal)
                        Next
                    End If
                    If TypeOf spesctl Is PlaceHolder Then
                        Dim plhctl As Control
                        For Each plhctl In spesctl.Controls
                            Me.Get_Ratings(plhctl, grouptotal)
                        Next
                    End If
                Next
            ElseIf TypeOf pesctl Is AjaxControlToolkit.Rating Then
                Dim ajrating As AjaxControlToolkit.Rating = pesctl
                grouptotal = grouptotal + ajrating.CurrentRating
            End If
        Next
    ElseIf ctl.Controls.Count > 0 Then
        Dim sctl As Control
        For Each sctl In ctl.Controls
            Me.Get_Ratings(sctl, grouptotal)
        Next
    End If
End Sub

我的问题是，如何有效地循环这种类型的结构以找到评级控件？

Answer 1

抱歉，我的VB.NET并不是那么好，但是递归函数看起来不像：

Protected Function GetRatings(ByVal control As Control) As IEnumerable(Of AjaxControlToolkit.Rating)
  If (control.Controls.Count > 0) Then
    Dim result As New List(Of AjaxControlToolkit.Rating)()

    For Each child In Control.Controls
      Dim rating As AjaxControlToolkit.Rating = child As AjaxControlToolkit.Rating
      If Not (rating Is Nothing) Then
        result.Add(rating)
      Else
        result.AddRange(GetRatings(child))
      End If  
    Next

    Return result
  Else
    Return Enumerable.Empty(Of AjaxControlToolkit.Rating)()
  End If
End Function

你不能做一个总结：

Dim controls As IEnumerable(Of AjaxControlToolkit.Rating) = GetRatings(control)
Dim total As Int32 = Enumerable.Sum(Of AjaxControlToolkit.Rating)(_
    controls, Function(rating) rating.CurrentRating)

如果语法不通，请告诉我，我通常不会做VB.NET

Answer 2

以下代码完全符合我的需求。我没有测试AjaxControlToolkit.Rating类型。

使用

调用sub

 getcontrols(Page.Controls)

这是子

 Sub getcontrols(ByVal obControls As ControlCollection)
    Dim sContent As String = ""

    For Each childcontrol As Control In obControls

        If childcontrol.HasControls Then
            setcontent(childcontrol.Controls)
        End If

        If childcontrol.GetType() Is GetType(AjaxControlToolkit.Rating) Then

            Dim sID = CType(childcontrol, AjaxControlToolkit.Rating).ID
            'DO SOMETHING

        End If
    Next 
End Sub

用于循环用户控件的正确逻辑

2 个答案: