Question

I’m OK with C# and VB.nET

I have a DataList (Question) inside the ListView (Section). ListiView is to hold the sections. DataList holds the questions of a section. Let’s say I have 3 sections, each section has 2 questions.

<asp:ListView ID="lvSection" runat="server">
    <LayoutTemplate>
        <div id="itemPlaceholder" runat="server" />
    </LayoutTemplate>    
    <ItemTemplate> 
        <div>
            <p><%#Eval("Section")%>
                <asp:HiddenField ID="hfSectionId" runat="server" Value='<%#Eval("SectionId")%>' />
                <hr />
            </p> 
        </div>
        <asp:DataList ID="dlQuestion" runat="server"  >
            <ItemTemplate>
                <asp:Label ID="lblQuestion" runat="server" Text='<%# Eval("Question") %>'></asp:Label>
                <asp:HiddenField ID="hfQuestionId" runat="server" Value='<%# Eval("QuestionId") %>' />
            </ItemTemplate>
        </asp:DataList>
    </ItemTemplate>            
</asp:ListView>

<br/>

<asp:Button runat="server" Text="Submit" onclick="Submit_Click" />

I’m trying to access the DataList dlQuestion when the button “Submit” is click like this:

Protected Sub Submit_Click(ByVal sender As Object, ByVal e As EventArgs)
    'but I need to loop through all DataLists inside the ListView
    'Maybe there are ways to get all the DataLists into a collection and then can loop through each one of them

    'this will get only one DataList. Here's the pseudocode

     Dim question As DataList = lvSection.FindControl("dlQuestion")
     For Each item As DataListItem In quest.Items
         Dim questionId As HiddenField = item.FindControl("hfQuestionId")
     Next
     End Sub

But it does not get anything back, question always gets nohting. I think it’s because there are 3 DataList inside the ListView now, due to 3 sections, and it cannot find DataList dlQuestion anymore. How do I access these DataLists of ListView from the code behind? I need to loop through each control of the DataList .

Thank you.

Answer 1

You would need to do it as this:

for each item As ListViewDataItem in lvSection.Items
    Dim list As DataList = item.FindControl("dlQuestion")
    If (list IsNot Nothing) Then
        For Each dlItem As DataListItem In quest.Items

            Dim questionId As HiddenField = dlItem.FindControl("hfQuestionId")

        Next
    End If
Next

You have to access the data list in each item in the ListView first, not at the listview level.