How to call method in main activity from other activity?

Question

I want to call public method in main activity from other activity. How can I do that?

class MainActivity extends Activity {
    public void myMethod() {}
}

         


        

Answer 1

Make it static, pass in the activity, instantiate, or better yet rethink design approach? I don't think you should be calling a method in another activity from your main activity - might be better to make a new class?

Static Code:

class MainActivity extends Activity 
{
    public void myMethod() 
    {
        MyActivity.runMyMethod();
    }
}


class MyActivity extends Activity 
{
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
    }

    public static void runMyMethod() 
    {
        //Run code...
    }
}

Instantiate Activity:

class MainActivity extends Activity 
{
    public void myMethod() 
    {
        MyActivity myActivity = new MyActivity();
        myActivity.runMyMethod();
    }
}

class MyActivity extends Activity 
{
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
    }

    public void runMyMethod() 
    {
        //Run code...
    }
}

Pass Activity Reference:

class MainActivity extends Activity
{
    public void onCreate(Bundle savedInstanceState)
    {
            OtherActivity otherActivity = new OtherActivity(this);
    }

    public void yourMethod()
    {
    }

}

class OtherActivity extends Activity
{
    MainActivity mainRefrence;
    OtherActivity(MainActivity main)
    {
        mainRefrence = main;
    }

    public void onCreate()
    {
        mainRefrence.yourMethod();
    }
}