Also worth remembering is that there are different types of MVPs as well. Fowler has broken the pattern into two - Passive View and Supervising Controller.
When using Passive View, your View typically implement a fine-grained interface with properties mapping more or less directly to the underlaying UI widget. For instance, you might have a ICustomerView with properties like Name and Address.
Your implementation might look something like this:
public class CustomerView : ICustomerView
{
public string Name
{
get { return txtName.Text; }
set { txtName.Text = value; }
}
}
Your Presenter class will talk to the model and "map" it to the view. This approach is called the "Passive View". The benefit is that the view is easy to test, and it is easier to move between UI platforms (Web, Windows/XAML, etc.). The disadvantage is that you can't leverage things like databinding (which is really powerful in frameworks like WPF and Silverlight).
The second flavor of MVP is the Supervising Controller. In that case your View might have a property called Customer, which then again is databound to the UI widgets. You don't have to think about synchronizing and micro-manage the view, and the Supervising Controller can step in and help when needed, for instance with compled interaction logic.
The third "flavor" of MVP (or someone would perhaps call it a separate pattern) is the Presentation Model (or sometimes referred to Model-View-ViewModel). Compared to the MVP you "merge" the M and the P into one class. You have your customer object which your UI widgets is data bound to, but you also have additional UI-spesific fields like "IsButtonEnabled", or "IsReadOnly", etc.
I think the best resource I've found to UI architecture is the series of blog posts done by Jeremy Miller over at The Build Your Own CAB Series Table of Contents. He covered all the flavors of MVP and showed C# code to implement them.
I have also blogged about the Model-View-ViewModel pattern in the context of Silverlight over at YouCard Re-visited: Implementing the ViewModel pattern.
