title: Interface defining a constructor signature?
body: <p>It's weird that this is the first time I've bumped into this problem, but:</p>
  
  <p>How do you define a constructor in a C# interface?</p>
  
  <p><strong>Edit</strong><br>
  Some people wanted an example (it's a free time project, so yes, it's a game)</p>
  
  <p>IDrawable<br>
   +Update<br>
   +Draw</p>
  
  <p>To be able to Update (check for edge of screen etc) and draw itself it will always need a <code>GraphicsDeviceManager</code>. So I want to make sure the object has a reference to it. This would belong in the constructor.</p>
  
  <p>Now that I wrote this down I think what I'm implementing here is <code>IObservable</code> and the <code>GraphicsDeviceManager</code> should take the <code>IDrawable</code>...
  It seems either I don't get the XNA framework, or the framework is not thought out very well.</p>
  
  <p><strong>Edit</strong><br>
  There seems to be some confusion about my definition of constructor in the context of an interface. An interface can indeed not be instantiated so doesn't need a constructor. What I wanted to define was a signature to a constructor. Exactly like an interface can define a signature of a certain method, the interface could define the signature of a constructor.</p>