为什么我不能在UpdateProgress div下更改标签？

Question

<asp:UpdateProgress ID="PreLoader" runat="server" ClientIDMode="Static">
    <ProgressTemplate>
        <div class="divWaiting">
            <asp:Image ID="preload" runat="server" ImageUrl="/Images/preloader.gif" />&nbsp
            <asp:Label ID="pmtProc1" runat="server" Text="Payment Processing ... Please Wait" ></asp:Label>
        </div>
    </ProgressTemplate>
</asp:UpdateProgress>

I can't seem to access pmtProc1 in my code-behind, why?

Answer 1

Any server-side control within a template (as used by things like <asp:Repeater> , <asp:GridView> and <asp:UpdateProgress> for example) are not directly contained by the page.

In this case you need to do a .FindControl on the <asp:UpdateProgress> control itself...

For instance...

Label pmtProc1 = (Label)PreLoader.FindControl("pmtProc1");
pmtProc1.Text = "New Text";

Note , this won't work with controls where multiple templates can occur (such as <asp:Repeater> and <asp:GridView for example)... in this situation you need to find the item in question and then find the control within that item.

For instance...

Label lbl = (Label)myRepeater.Items[0].FindControl("myLabel");