Why cant WPF's MainWindow be a WCF service?

I have a WPF app that will show youtube videos on my tv via a media center pc. This app will receive commands to PlayVideo(string VideoId), PauseVideo(), etc via a WCF service hosted inside the WPF app.

This is a newbie question, but why can my MainWindow not implement the service contract and then be used as the service using the new ServiceHost() constructor that takes an obj开发者_开发问答ect singleton in?

When I try I get this exception:

System.InvalidOperationException: Service 'Desktop.MainWindow' has zero application (non-infrastructure) endpoints. This might be because no configuration file was found for your application, or because no service element matching the service name could be found in the configuration file, or because no endpoints were defined in the service element.

My reasoning for doing this is that the simple commands needs to end up at the window anyway, so why not just have the window receive the messages directly instead of indirectly via subscribing to events on the service or having the service have a reference to the MainWindow and call methods on it.

The error, System.InvalidOperationException: Service 'Desktop.MainWindow' has zero application , simply means your app.config (if you have one) does not have the endpoints or the A,B,C's setup correctly (address, binding, contract).

You can host a wcf service in a winform or wpf form, you would only want to do that maybe for a test project in some kind of proof of concept work but never in an application you plan to give to a client or a real user.

If you're new to WPF I strongly recommend reading up on the Model-view-view-Model design pattern. This will allow you to implement the WCF service abstracted away from the UI in your WPF app and will give you a better separation of concerns and responsibilities for the logic in your app.

If you were writing code that others were going to maintain then I'd say...

Why not? Because you're mixing areas of responsibility. The Main Window doesn't need to know anything about WCF, it's job is to present things on screen.

Given that it's your app for your own personal needs, nobody cares what structure you use (just don't ask someone else to maintain it!) :) Having said that, if you want to make it easy for yourself to modify, I'd suggest making an effort to keep the code clean. What you're aiming to do, in my view, doesn't fit that description.

Your mainwindow probably could implement that Service Contract, but I think it's a very bad idea.