Hi all,

I am using RadAjaxLoadingPanel and RadAjaxPanel with a Button which takes long time processing (Communicating with external machine), this is the code.

<telerik:RadAjaxLoadingPanel ID="RadAjaxLoadingPanel1" Runat="server">
      <img alt="Loading..." src="loading.gif">
</telerik:RadAjaxLoadingPanel>

<telerik:RadAjaxPanel ID="RadAjaxPanel1" LoadingPanel="RadAjaxLoadingPanel1">
      <asp:Button ID="btn" runat="server" OnClick="btnClick" Text="Clieck here" />
</telerik:RadAjaxPanel>

protected void btnClick(object sender, EventArgs e)
{
      Foo() // function takes long time
}

After pressing this button it shows me this error message
Microsoft JScript runtime error: Sys.InvalidOperationException: A Control in already associated with the element

Is there anyway else to show loading image?????

another thing, that I tried to show loading with Gridview but it doesn't come. how to show loading with the GridView events???

Thank in advance

Hi Fouad,

Could you please test the application by using regular asp Update Panel instead of radAjaxPanel?Also please elaborate a little bit more on the issue you are facing. Does the error appear if the RadAjaxLoadingPanel is removed from the page?

Kind regards,
Maria Ilieva
the Telerik team

I've got the exact same problem and:

1.  I'm using the UpdatePanel
2.  The Error disappears when "RadAjaxLoadingPanel is removed from the page"

Hello,

Could you please open a regular support ticket and send us runnable application which demonstrates the error. We will test it locally and advise you further.


Sincerely yours,
Maria Ilieva
the Telerik team