C# AJAX Web methods - What am I doing wrong???

Question

This maybe a very noobish question but I am trying to implement a simple web method using AJAX C# and asp.net here is the code:

C# code behind:

using System.Web.Services;

public partial class Controls_LeftNavigation : System.Web.UI.UserControl
{
    [WebMethod]
    public static string MyMethod()
    {
        return "Hello";
    }
}

Asp.net page:

<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true">
</asp:ScriptManager>

<script type="text/javascript">
            function pageLoad() {
                var acc = $find('<%= Accordion1.ClientID %>_AccordionExtender');
                acc.add_selectedIndexChanging(ClickHandler);
            }
            function ClickHandler() {
                // Do whatever you want.
                alert('Something is happening!');
                alert(PageMethods.MyMethod());
            }
</script>

when the navigation button is clicked it displays the "Something is happening!" message box but does not show the page method alert.

I am using the ASP AJAX toolkit accordion which is why the page load event adds the click handler event to that control.

Answer 1

The page method is asynchronous, you must provide an onSuccess handler like so:

function OnSuccess(result) {
   alert(result);
}

function ClickHandler() {
   PageMethods.MyMethod(OnSuccess);
}

You will also need to prevent the SelectedIndexChanging event from doing a Post Back or else the page will not be able to handle the returning result.

Answer 2

PageMethods on user controls are not supported.