ASP.NET Debugging Tip with Application_Error

Often when you are debugging an ASP.NET application you find that something you "think" should work doesn't work, or you get a blank page. Wiring up the unhandled exception handler in Global.asax.cs (vb) can help solve these problems.

Here is some sample code from Global.asax.cs:

void Application_Error(object sender, EventArgs e)
        {
            Exception ex = Server.GetLastError().GetBaseException();
           // SET A BREAKPOINT ON THE NEXT LINE AND LEAVE IT THERE.
           System.Diagnostics.Debug.WriteLine( ex.ToString() );
      
           Server.ClearError();
        }

Application_Error is the ASP.NET equivalent of the unhandled exception "holder of last resort". When something in a page goes wrong, if you have the above code wired up, you'll find out about it right away.

This simple technique can save you hours of frustration. Try it!