如何在Android Studio中的其他类中访问ImageButton？

Question

So Im new to Android Studio and I havn't been getting any help through Google. So my problem is that I'm trying to access an ImageButton from another class rather than just putting that method in the MainActivity .

My second question is, am I doing this the wrong way? How would you solve this without having to put that method of changing pictures in the MainActivity which I did before (it worked too but started to look messy).

So this is the Player class :

public class Player extends ActionBarActivity {

    public Player(){
    }
    public void changeThatPicture(int siffra){

        ImageButton imgBtn = (ImageButton) findViewById(R.id.tarning);
        switch(siffra){
            case 1: imgBtn.setImageResource(R.drawable.one); break;
            case 2: imgBtn.setImageResource(R.drawable.two); break;
            case 3: imgBtn.setImageResource(R.drawable.three); break;
            case 4: imgBtn.setImageResource(R.drawable.four); break;
            case 5: imgBtn.setImageResource(R.drawable.five); break;
            case 6: imgBtn.setImageResource(R.drawable.six); break;
        }
    }

}

And here is from my MainActivity:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Player p1 = new Player();
    number = 1 + random.nextInt(6);
    p1.changeThatPicture(number);

    playGame();
}

Answer 1

You can try something like this;

From MainActivity

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ImageButton btn = (ImageButton) findViewById(R.id.tarning)
    number = 1 + random.nextInt(6);
    Player.changeThatPicture(btn, number);

    playGame();
}

A Plain class, no need to extend activity it just add confusion and mess. The method is made static so you don't need to instantiate it to use the method.

public class Player  {

    public static void changeThatPicture(ImageButton imgBtn, int siffra) {
        switch(siffra){
            case 1: imgBtn.setImageResource(R.drawable.one); break;
            case 2: imgBtn.setImageResource(R.drawable.two); break;
            case 3: imgBtn.setImageResource(R.drawable.three); break;
            case 4: imgBtn.setImageResource(R.drawable.four); break;
            case 5: imgBtn.setImageResource(R.drawable.five); break;
            case 6: imgBtn.setImageResource(R.drawable.six); break;
        }
    }

}