监听上下左右键

 public boolean onKeyDown(int keyCode, KeyEvent event) {         switch (keyCode) {         case KeyEvent.KEYCODE_DPAD_CENTER:             display("中键报道，被按下");             break;         case KeyEvent.KEYCODE_DPAD_DOWN:             display("下键报道，被按下");             break;         case KeyEvent.KEYCODE_DPAD_LEFT:             display("左键报道，被按下");             break;         case KeyEvent.KEYCODE_DPAD_RIGHT:             display("右键报道，被按下");             break;         case KeyEvent.KEYCODE_DPAD_UP:             display("上键报道，被按下");             break;         }         return super.onKeyDown(keyCode, event);     }