Question

I’m working on a ASP.NET site with C# code.
Now the trouble starts when I create a custom control programmatically. The control displays in a panel, but when I click one of the buttons of the control it does nothing. If I click them twice, the user control disappears.
Using the debugger, I found that it’s doing a postback, which is strange because I tried using buttons and setting the usesubmitbehavior to false; it’s still sending postbacks.

Here is where the control is inserted on the default.aspx file

<asp:UpdatePanel runat="server" ID="contentHolderUpdatePanel"
                UpdateMode="Conditional">
   <ContentTemplate>
       <asp:Panel runat="server" ID="contentPanel">
       </asp:Panel>
   </ContentTemplate>
</asp:UpdatePanel>

Here is the ASPX from ListadoAuditoria of the control.

<asp:UpdatePanel runat="server" ID="auditorTableUpdatePanel" UpdateMode="Conditional">
 <ContentTemplate>
     <asp:Table runat="server" ID="auditorTable" BorderWidth="0" Width="100%">
         <asp:TableHeaderRow HorizontalAlign="Center">
             <asp:TableHeaderCell>Button
             </asp:TableHeaderCell>
         </asp:TableHeaderRow>
     </asp:Table>
 </ContentTemplate>
</asp:UpdatePanel>
<asp:UpdatePanel runat="server" ID="formHolderUpdatePanel" UpdateMode="Conditional">
<ContentTemplate>
<asp:Label runat="server" ID="testLabel" Text="bbbbbbbbbbbbb" ></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>

The method that the button invokes should change the text of the label testLabel from “bbbbbbbbbbbbb” to “aaaaaaaaaaa”. Obviously I’m doing an auditorTableUpdatePanel.Update() after I modify the text.

The control CS

    protected void Page_Load(object sender, EventArgs e)
    {
        loadAudits();
    }

    public void loadAudits()
    {

        for(int i=0;i<10;++i)
        {
            TableRow row = new TableRow();

            TableCell cell1 = new TableCell();

            ImageButton deleteButton = new ImageButton();
            deleteButton.ImageUrl = "~/image.gif";
            deleteButton.Click += generateNewPart;
            deleteButton.EnableViewState = true;
            deleteButton.ID = i.ToString();

            cell1.Controls.Add(deleteButton);

            row.Cells.Add(cell1);

            auditorTable.Rows.Add(row);

        }
    }

    public void generateNewPart(object sender, EventArgs e)
    {
        tumadre.Text = "aaaaaaaaaaaa";
        formHolderUpdatePanel.Update();
    }

And here is the code when I generate the control and insert it into the panel:

Panel panel = (Panel)Page.FindControl("contentPanel");
UpdatePanel updatePanel = (UpdatePanel)Page.FindControl("contentHolderUpdatePanel");
ListadoAuditorias listadoAuditorias = (ListadoAuditorias)LoadControl("~/CargaDeAuditoria/ListadoAuditorias.ascx");
panel.Controls.Add(listadoAuditorias);
updatePanel.Update();

I looked over the Internet and didn’t found anything.

Answer 1

I’m not sure where exactly the code to dynamically add the controls is, but it must be called on EVERY postback to re-add the controls. You can’t just add it once and forget about it. When you postback, the page will re-render with the markup in your aspx page (which does not have your dynamic controls, obviously). The values from the dynamically added controls will still be in ViewState, but the controls will not be re-rendered.