Display a random image when a button is clicked

Question

I tried earlier and just got more confused so i will try and be more precise. I am making an app in which i have a deck of 7 cards. I want to click on the deck and have one of

Answer 1

Try this way

 int[] cards={R.drawable.card1,R.drawable.card2,R.drawable.card3,R.drawable.card4,R.drawable.card5,R.drawable.card6,R.drawable.card7};
 Random r = new Random();
 int n=r.nextInt(7);
 imageview.setImageResource(cards[n]);