Can I create an object of an Activity in other class?

Question

I have defined a function in MainActivity now I want to access the function from another class in my app. I have created an object of the MainActivity and with that object I have called the function. Although there is no error, it's not executing. Every time I try to execute, the app crashes.

Answer 1

Activity A should have a variable

static ActivityA activityA;

In onCreate state:

activityA = this;

and add this method:

public static ActivityA getInstance(){
   return   activityA;
 }

In activity B, call

ActivityA.getInstance().myFunction(); //call myFunction using activityA