Question

The Repeater control in the following test case contains two runat=”server” DIVs. Each one of them gets a TextBox appened to them through the ItemCreated event of the Repeater. Both of the have AutoPostBack=True, and TextChanged event wired to txt_TextChanged. However, only the TextBox from the first level properly points to the event on the postBack of the page. The second level TextBox also causes the postBack to occur, but its value does not persist in the VIEWSTATE as well as the event does not fire.

Here’s a direct link to the test case in a .zip file (uploaded to my personal website), as well as all the code needed. The project is built in VS2010 using .NET Framework 4, but the problem also exists in 1.1, 2, and 3.5.

Anybody has any ideas on what is wrong and how to make this work?

ASPX

<asp:Repeater ID="rep" runat="server">
    <ItemTemplate>
        <!-- first level works -->
        <div id="divOutside" runat="server">
            <!-- second level doesn't work -->
            <div id="divInside" runat="server"></div>
        </div>
    </ItemTemplate>
</asp:Repeater>

Code-Behind

Public Class WebForm1
    Inherits System.Web.UI.Page

    Private Sub WebForm1_Init(sender As Object, e As System.EventArgs) Handles Me.Init
            If Not IsPostBack Then
                    Dim Table As New DataTable()
                    Table.Columns.Add("Column1")
                    Dim Row As DataRow = Table.NewRow()
                    Row("Column1") = ""
                    Table.Rows.Add(Row)

                    rep.DataSource = Table
                    rep.DataBind()
            End If
    End Sub

    Private Sub repTest_ItemCreated(sender As Object, e As System.Web.UI.WebControls.RepeaterItemEventArgs) Handles rep.ItemCreated
            ' outside
            Dim divOutside As HtmlGenericControl = DirectCast(e.Item.FindControl("divOutside"), HtmlGenericControl)
            Dim txtInput As New TextBox
            With txtInput
                    .ID = "txtInputOutside"
                    .AutoPostBack = True
                    .Text = "Event gets called, value persists accross postBack."
                    .Width = 400
            End With
            AddHandler txtInput.TextChanged, AddressOf txt_TextChanged
            divOutside.Controls.Add(txtInput)

            ' inside
            Dim divInside As HtmlGenericControl = DirectCast(e.Item.FindControl("divInside"), HtmlGenericControl)
            txtInput = New TextBox
            With txtInput
                    .ID = "txtInputInside"
                    .AutoPostBack = True
                    .Text = "Event NOT called, value is lost during postBack."
                    .Width = 400
            End With
            AddHandler txtInput.TextChanged, AddressOf txt_TextChanged
            divInside.Controls.Add(txtInput)
    End Sub

    Protected Sub txt_TextChanged(sender As Object, e As EventArgs)
    End Sub
End Class

Answer 1

Here’s a link to Microsoft Connect, where I reported this is an official bug:
https://connect.microsoft.com/VisualStudio/feedback/details/652655/asp-net-bug-in-event-linking-of-2nd-level-dynamic-controls

It contains 2 PARTIAL workarounds that work in the uploaded files section, if anybody is interested or encounters the same problem, as well as details to what I found in the Workarounds tab.

To keep it short, it is the order of getting references to the containers and the order the TextBoxes are appended to their appropriate containers which either causes the issue or works as expected.

But, not to forget the most important point, the only reason the first-level TextBox is there in the first place is to showcase what I want as functionality. If the first-level TextBox does not get appended at all, then both workarounds fail to provide any sort of fix. Please keep that in mind when reviewing that problem – finding a workaround that revolves around changing the order of the items is not an actual solution or a fully working workaround!

Thanks everyone for the input!