What are assembly references for GetValue/SetValue for creating DependancyProperty

I have a hard time setting up a Silverlight Class Library project. In this project, I am trying to create a dependancy开发者_如何学Go property. The code requires to use SetValue and GetValue methods -- the project cannot resolve these methods. What do I need to reference to access these methods? Thank you for help.

I forgot to derive the class, which implements the dependancy property, from the "Control" base class. The reference to SetValue and GetValue methods now appear to be resolved.

public class ClassName: Control { ... }