Get a C# Class Library to have WCF services?

Question

How can I get a C# class library to have WCF services? I have WCF services added in there, just that I can't get it to run since it complains that the project type of Class library cannot be set as startup. Any ideas?

Answer 1

Well, the WCF service implementation in your class library needs to be hosted somewhere - either in IIS (like the legacy ASMX web services), or you can self-host.

See MSDN for How to host a WCF service in a managed application (self-hosting) or How to host a service in IIS.

In addition, Visual Studio 2008 also has a "generic" service host application in its Common7/IDE folder, called "WcfSvcHost.exe". See the MSDN docs on that. You can set up your Visual Studio class library project to automatically launch this service host app to host your service, so you can test it.

Answer 2

Indeed, a dll isn't usually "executed" as such. There are hosts for dlls (COM+, for example), but typically you would have either an exe (perhaps a service) or IIS (or another web-server) act as the host process. For an example, see MSDN.

For re-use purposes it is fine to have the "real" code in the dll, and have the host exe a 5-liner that just calls into the dll (allowing you to use the dll in other scenarios).