监听不到android 的 Home 键

应用程序监听不了android 机的HOME KEY事件。

 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
  // TODO Auto-generated method stub
  if(keyCode==3)//HOME键码为3
  {
   HomeKeyNum+=1;
   Log.i("gogler", "home key pressed time is: "+HomeKeyNum);
  }
  return super.onKeyDown(keyCode, event);
 }

实验结果没有预期日志输出，把键码换成BACK键码4则可以监听到。

官方解释：

Key code constant: Home key. This key is handled by the framework and is never delivered to applications.