Patrick Cooney's Weblog

One little thing I'd like to see changed in C#

2004-01-28

I love explicit interface implementation in .NET, where a method defined on an interface can only be called through a reference to that type.

	public interface IFoo {
		void DoFoo();
	}

	public class Bar : IFoo {
		void IFoo.DoFoo() {
			...
		}
	}

This forces Bar clients to program against the IFoo interface, which makes implementation substitution an easy process. Sounds good so far? It is, until I want to call DoFoo() from within Bar. Instead of making a regular call to

	DoFoo();

Or even

	IFoo.DoFoo();

I have to go to the trouble of casting 'this' to IFoo

	(this as IFoo).DoFoo();

Under the covers, the explicit interface implementation method is compiled as a private method with the name interfaceName.methodName. The code I use to call this (above) corresponds pretty well to the IL that I need to invoke the method, but it seems like a little bit of extra typing. Can't the compiler do this for me?

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