循环用户控件的正确逻辑

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。用户控件内有四个控件：标题标签、Repeater、Placeholder，Repeater 内有一个 AjaxControlToolkit Rating 控件。

该结构可能如下所示：

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 不是那么好，但是递归函数不会类似于：

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

你不能做一个求和吗：

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

如果语法有问题，请告诉我，我通常不会这样做网络

Answer 2

下面的代码非常适合我的需求。我没有测试 AjaxControlToolkit.Rating 类型。

调用子程序

 getcontrols(Page.Controls)

使用Here is the sub

 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