I am a bit puzzle by this problem.

I have created a library assembly with visual studio 2010 that exposes several things, like observable collections and methods to report some data.

Then I created a WPF project in Expression Blend 4 that has a reference to this assembly and I also created a datasource object from this assembly. So far so good.

When I look in the data view of Blend 4, I can see the observable collections and methods of the data source. I can successfully bind the observable collection to a datagrid or bind the method in XAML to a button.

But, in a very specific case, I need to programmatically call one of the methods of the datasource in my cs file. What should I do?