Debugging WCF Services in Visual Studio 2008

One of the new features that we added in Visual Studio 2008 was debugger enhancement for Windows Communication Foundation (WCF) services.

There are four features that we support:

  1. You can step from a service client into the implementation. Just step into ('F11') a web service proxy and the debugger will automatically go and attach to the server process and stop when execution reaches the service implementation.
  2. You can step out of the implementation of a service back into the client.
  3. You can get a logical call stack which shows the client and server (see below).
  4. The debugger can automatically attach to services in your solution whenever the debugger sees a service request going to the service. This allows you to hit breakpoints in your service without having to go and explicitly stepping into it.

Logical Call Stack

There is more information about these features in our documentation: The first three of these features also exist for ASP.NET web services and have been included in Visual Studio for several releases. The fourth feature is new.

There is one troubleshooting item that I wanted to mention because it is not included in our documentation. If you are finding that none of these features seem to be working, it is possible that something has gone wrong with the installation and that the necessary machine.config changes did not happen. To resolve this, we shipped a tool to manually install/uninstall the necessary changes:

  1. Start a command prompt (Start->Run, cmd.exe). Note that this will get you a 64-bit command prompt on a 64-bit OS, which is what you want. If you are running on Vista, you need to start this command prompt as an Administrator.
  2. Change directory to the root of your VS installation (if you installed to the default location: cd /d "%ProgramFiles%\Microsoft Visual Studio 9.0\Common7\IDE")
  3. Run: vsdiag_regwcf.exe -i

You could also use the '-u' flag if you some reason you want to disable this integration.