Question

我需要能够隐藏从动态项目符号列表（在DetailsView内部构建）中显示的2个选项。每次我尝试通过BulletedList编写一个循环时，我都会收到一个错误，说它不是一个集合类型，所以我想我可以遍历DetailsView来找到我想要隐藏的项目。

我无法更改SQL，因为这个特定的项目符号列表在2个不同的页面上使用，只是在一个页面上，我只需要显示与ID相关联的4个项目中的2个。

<asp:TemplateField HeaderText="Answer(s)" SortExpression="PicklistID">
        <ItemTemplate>
            <asp:HiddenField ID="hiddenPicklistID" runat="server"  
            Value='<%# Bind("PicklistID") %>' />
            <asp:BulletedList ID="blText" runat="server" DataSourceID="dsPicklist" 
            DataTextField="TEXT">
            </asp:BulletedList>
        <asp:SqlDataSource ID="dsPicklist" runat="server" 
        ConnectionString="<%$ ConnectionStrings:SurveyConnectionString %>" 
        SelectCommand="SELECT p.TEXT FROM PICKLIST p 
                       JOIN C_Survey_Questions c 
                       ON p.PICKLISTID = c.PicklistID 
                       AND c.QuestionID = @QuestionID 
                       AND c.SurveyID = @SurveyID 
                       WHERE p.PICKLISTID IS NOT NULL 
                       AND c.PicklistID IS NOT NULL">
            <SelectParameters>
                <asp:ControlParameter ControlID="DropDownList1" Name="SurveyID" 
                PropertyName="SelectedValue" Type="Int32" />
                <asp:ControlParameter ControlID="hiddenQuestionID" Name="QuestionID" 
                PropertyName="Value" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>
        </ItemTemplate>
    </asp:TemplateField>

我试过了：

    Protected Sub blText_DataBound(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim blText As BulletedList
    For Each BulletedListItem In blText

    Next
End Sub

但Visual Studio告诉我它不是集合类型。所以我想我可以在下面的代码中添加For Each。我不知道如何遍历DetailsView，有人能指出我在正确的方向吗？

Protected Sub dvSurveyQuestions_DataBound(ByVal sender As Object, ByVal e As
System.EventArgs) Handles dvSurveyQuestions.DataBound
End Sub

UPDATE 2/6：我使用FindControl声明了我的BulletedList，并且没有更多的错误说没有声明BulletedList。

Protected Sub blText_DataBound(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim blText As BulletedList = dvSurveyQuestions.FindControl("blText")
    For Each i As ListItem In blText.Items

    Next
End Sub

另一个更新：我需要获得33的唯一QuestionID的blText.DuesrseID是一个Integer，但我不知道如何将HiddenField与Integer字段相关联。在此代码中，“Is”加下划线表示Is operator does not accept opeands of type 'Integer.'所以我将Is更改为an =并得到错误Operator = is not defined for types HiddenField and Integer.

Dim QuestionID = DirectCast(dvSurveyQuestions.FindControl("hiddenQuestionID"), HiddenField)
    If QuestionID Is 33 Then
        Dim blText As BulletedList = dvSurveyQuestions.FindControl("blText")
        For intCursor = (blText.Items.Count - 1) To 0 Step -1
            If blText.Items(intCursor).Text = "Self Directed" Or "Systems" Then
                blText.Items.RemoveAt(intCursor)
            End If
        Next
    End If

这是有效的

 Dim QuestionID As Integer = CInt(CType(dvSurveyQuestions.FindControl("hiddenQuestionID"), HiddenField).Value)
    If QuestionID = 33 Then
        Dim blText As BulletedList = dvSurveyQuestions.FindControl("blText")
        For intCursor = (blText.Items.Count - 1) To 0 Step -1
            If blText.Items(intCursor).Text = "Self Directed" Or blText.Items(intCursor).Text = "Systems" Then
                blText.Items.RemoveAt(intCursor)
            End If
        Next
    End If

Answer 1

从BulletList的Items属性循环。

    For Each i As ListItem In blText.Items

    Next

这可能更具体针对您的问题...

    For intCursor = (blText.Items.Count - 1) To 0 Step -1

        If blText.Items(intCursor).Text = "TextValueToRemove" Then

            blText.Items.RemoveAt(intCursor)

        End If

    Next

循环DetailsView以隐藏动态BulletedList项

1 个答案: