int[] Srcimagers={R.drawable.shake,R.drawable.shake1,R.drawable.shake2,R.drawable.shake3};
//隨機生成圖片
Random random=new Random();
int strImage=Srcimagers[random.nextInt(4)];
//圖片路徑
imageView.setImageResource(strImage);
random.nextInt(4)生成的隨機數是0,1,2,3,