I'm a bit new to Android Programming (few months) and today, I faced the same problem you did (maybe you still do?)
I made it work as the following :
Lets say I have MainActivity, and in MainActivity I have Btn2 which leads to SecondActivity, and Btn3 which leads to ThirdActivity.
I declared at the beginning of MainActivity :
public static boolean shouldPlay = false;
I then implemented my onStop() method :
public void onStop() {
super.onStop();
if (!shouldPlay) { // it won't pause music if shouldPlay is true
player.pause();
player = null;
}
}
If the boolean shouldPlay is set to true, then my onStop() won't be called entirely and my music won't turn off. I then have to decide when I set it to true. When I switch from MainActivity to SecondActivity, I do it through an Intent and that's when I'll set shouldPlay to true :
Button Btn2 = (Button) findViewById(R.id.Btn2);
Btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, SecondActivity.class);
shouldPlay = true;
startActivity(intent);
}
});
And the same is done for Btn3.
Now, the last thing we want to be looking for is that if I was to go back to MainActivity after visiting SecondActivity or ThirdActivity, shouldPlay would then have been set to true. The first thing I tried was to set it to false as soon as Second and ThirdActivity are called (in their onCreate()) but it want to work, maybe because the onStop() from Main and onCreate() from others are called simultaneously (frankly I don't really get life cycle for now). What worked is simply to set shouldPlay to false every time we launch onCreate() of Main :
shouldPlay = false;
This works properly for me. Let me know if it does for you, Cheers, bRo.