Question

How can I do this:

Class A : DependencyObject {}

Class B : DependencyObject {}

Class C : A , B {}

Answer 1

C# does not have multiple inheritance, so the line

Class C : A , B {}

will never work. You can do similar things with interfaces though, along the lines of

interface InterfaceA { void doA(); } 
class A : InterfaceA { public void doA() {} }

interface InterfaceB { void doB(); }
class B : InterfaceB { public void doB() {}}

class C : InterfaceA, InterfaceB
{
  m_A = new A();
  m_B = new B();

  public void doA() { m_A.doA(); }
  public void doB() { m_B.doB(); } 
}