How do I create a global exception handler for a WCF Services?

Question

I want to log all exceptions server side.

In ASP.NET I write something like this in Global.asax.cs, but will this work for a WCF service, too?

public class Global : HttpApplication
{
    protected void Application_Error(object sender, EventArgs e)
    {
        Exception unhandledException = Server.GetLastError();

        //Log exception here
        ...
    }
}

UPDATE: I don't want to have a try...catch for every [OperationContract] in my .svc file. I short... I want to make sure that all exception that my service throws is logged by log4net. I'm not talking about how the client handles exception.

Answer 1

You can create a WCF error-logger by implementing IErrorHandler and associating it with the service; typically (for logging) you would return false from HandleError (allowing other handlers to execute), and log the error either in HandleError (using the Exception) or in ProvideFault (using the ref Message fault).

I apply this handler by writing a custom behavior (inheriting from BehaviorBase), which (in ApplyDispatchBehavior) adds the error-handler to endpointDispatcher.ChannelDispatcher.ErrorHandlers if it isn't already there.

The behavior can be applied via configuration.