Prior to the July CTP of VS 2005, the ICallbackEventHandler had just one method with the following signature: string RaiseCallbackEvent (string eventArgument) The eventArgument was the string that came from the client and the return string went back to the client. In July CTP, the ASP.Net team split up the processing into two calls that now make up the ICallbackEventHandler: void PrepareCallbackEvent (string eventArgument)string RenderCallbackResult () The idea remains the same, you process the incoming data in PrepareCallbackEvent and put together the return payload in RenderCallbackResult.

Following up to my previous post, the urlMappings section in Web.config allows one to configure rudimentary url rewriting. For example, putting this into your section: <urlMappings>  <add url="~/PageThatDoesNotExist.aspx" mappedUrl="~/RealPage.aspx" /><urlMappings> will result in RealPage.aspx being rendered while the browser still thinks it reached PageThatDoesNotExist.aspx. One thing to note is that the URL must be application root relative. This was actually of interest to me since I wanted to do something similar but with a permanent redirect. It looks like in order to be able to do that, they had to bake urlMappings support pretty deep into the framework (way deeper than an...

Looking through the machine.config.comments found in \Windows\Microsoft.Net\Framework\{ver}\Config yields some curious things that I havent seen broadly discussed yet. This is a reminder to myself to dig a bit further. anonymousIdentificationurlMappingshttpCookiessessionPageState