android - How to get my activity context?

Question

I don't really get the idea behind how this whole thing works really, so if I have some class A that need the context of a class B which extends Activity, how do i get that context?

I'm searching for a more efficient way than giving the context as a parameter to class A constructor. For example if class A is going to have millions of instances then we would end up having millions of redundant pointer to Context while we should be able somehow to have just one somewhere and a getter function...

Answer 1

Ok, I will give a small example on how to do what you ask

public class ClassB extends Activity
{

 ClassA A1 = new ClassA(this); // for activity context

 ClassA A2 = new ClassA(getApplicationContext());  // for application context. 

}