Android对屏幕空白区域的监听方法：

  @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if(ev.getAction()==MotionEvent.ACTION_DOWN){
            View view = getCurrentFocus();
            if(view!=iv1){
                iv1.setVisibility(View.INVISIBLE);
            }
        }

        return super.dispatchTouchEvent(ev);
    }  @Override
    public boolean dispatchTouchEve