Learning WCF - Port contention issues during debugging

When working through exercises from the MSPress book on WCF for .NET 3.5 and from Bustamente's "Learning WCF" I ran into an issue when "self-hosting" WCF services in a console application.

One self-hosting example featured a solution with two projects:  1) a WCF service ("library") project and 2) a console app used to host the WCF service in the library project.   Each had an "app.config" file in it indicating that it wanted to use port 8080 under the local host URL:

... snip ...  <host> <baseAddresses> <add baseAddress="http://localhost:8080/NetStarCommandService" /> </baseAddresses> </host> ... snip ...

The solution built fine but when trying to run it presented this error message:

"HTTP could not register URL http://+:8080/NetStarCommandService/.  Another application has already registered this URL with HTTP.SYS"

If I changed the port number in either of the app.config files the code would run fine.

The problem turns out to be with a Visual Studio 2010 feature I was unaware of.  When you start a solution which has a WCF service in it Visual Studio will quietly start the WCF hosting service for the WCF service before running the code in the solution -- this causes the library project and the WCF hosting service to grab the port first and then prevent the self-hosting console code from running on that port.

The solution is very simple:  Right-click the WCF service project (the "library" project) in the solution, bring up its properties, and take a look at the "WCF Options" tab on the properties screen.  Uncheck the "Start WCF host when debugging another project in the same solution" checkbox and the project should run correctly.