Yesterday I posted a little quiz with an example of an HttpHandler implemented as an ASHX file.

Brad Wilson obviously knew the answer, but only gave a hint for others to elaborate on. BigJimSlade (no link given) expanded on the answer. BigJim, I have a GMail account for you if you want one.

Calling HttpResponse.Redirect(string url) actually calls an overload HttpResponse.Redirect(string url, bool endResponse) with endResponse set to true. If endResponse is set to true, HttpResponse.Redirect will make a call to HttpResponse.End().

That method in turn calls Thread.CurrentThread.Abort(). Oh the depravity! Once again, Thread.Abort rears its ugly head.

So as you see, the code sample will ALWAYS redirect to /default.aspx because the HandleRedirect method throws a ThreadAbortException every time. To fix this, I merely need to change the HandleRedirect method to call ctx.Response.Redirect("/special.aspx", false);.

The fact that this week seems to be “Thread.Abort Week” isn’t why I posted this quiz. I ran into this problem the other day in my carelessness. It’s a result of my old ASP 3.0 habits resurfacing after years of suppressing them. It took me a few minutes to realize why my code never made it to special.aspx.