Wednesday, 8 June 2011

Asynchronous operations are not allowed in this context

While calling a WCF service asynchronously from 'Code Behind' of my .Aspx page I got the following error:

Asynchronous operations are not allowed in this context. Page starting an asynchronous operation has to have the Async attribute set to true and an asynchronous operation can only be started on a page prior to PreRenderComplete event.


Add Async="true" to you Page directive i.e.
<%@ Page Language="C#" Async="true" ...

You can read more about Async attribute HERE.

BTW. The original error message was in Polish as I use localized operating system:

Operacje asynchroniczne nie są dozwolone w tym kontekście. Strona rozpoczynająca operację asynchroniczną musi mieć atrybut Async o wartości True. Operację asynchroniczną można uruchomić na stronie tylko przed zdarzeniem PreRenderComplete.

I translated it using the tool descriebd in my next post.

1 comment:

Mohammed Alani said...

Thanks alot. This did the trick.