Yesterday, I was doing a little work with Silverlight and I’ve got this little sample that I’m working on;

and one of the things that it does it talk XML or JSON to a back-end service depending on the value of the ComboBox up in the top right hand area.

I wanted to do a little diagnosing around this and, usually, I turn to Fiddler for this kind of diagnostic work but I’m running the IE9 RTM (download) and so I thought I’d use the network capture in there rather than rely on Fiddler. With a quick F12, I’m up and running;

and then I can exercise the Silverlight application a little and see the results of my HTTP GET and POST;

and zoom in to the detail view and see the JSON data coming back;

along with headers, etc…

and it’s all cool and quick to get going and you might even notice that it’s working for traffic to localhost which is something that I think Fiddler finds a bit tricky (although if I remember correctly, there’s workarounds here).

That said, this traffic was all carried by Silverlight’s browser HTTP stack which gets traced here by IE. If I switch to using Silverlight’s client HTTP stack then I don’t think IE (as you’d expect) has any visibility of that traffic and so it’s back to Fiddler at that point…