ICallbackEventHandler and Master Page

Guy g. · March 2nd, 2011, 08:08 AM

Hi

I'm trying to add a callback to my page which was created from a master page.
Unfortunatly, I always get an error:
"The target 'XXXPage' for the callback could not be found or did not implement ICallbackEventHandler."

When I tried it in a page which was not created from a master page everything works fine, as well as controls which implement ICallbackEventHandler and are located in the XXXPage.

Does anyone know what is the problem?

Thanks
Guy

disel2010 · March 2nd, 2011, 05:08 PM

Did you perhaps implement the ICallbackEventHandler in the master page and try to register the client script in the content page?
Then you would need to specify it to register in the master page:
Master.Page.ClientScript.GetCallbackEventReference (...);
Master.Page.ClientScript.RegisterClientScriptBlock ....);

Guy g. · March 3rd, 2011, 07:00 AM

The problem was in the content page.
I solved it with a workaround:
The page was in an inner folder so the type of the page was innerFolder_XXXPage but the
GetCallbackEventReference function returned 'XXXPage' as the first parameter to the callback.

When the Page.ProcessRequestMain check if the request is a callback, it does not find a control with such name so it raise an exception.

To solve it, I override the FindControl method in the page:

Code:

public override Control FindControl(string id)
{
 Control ctl = base.FindControl(id);
 if (IsCallback && ctl == null && id == this.Page.GetType().BaseType.FullName)
 {
    return this;
 }
 return ctl;
}

Guy