Android对屏幕下方经常使用的四个按键消息处理是不一致的：

1、搜索按键的消息在onKeyDown或者onKeyUp中接收；

2、菜单按键的消息在onCreateOptionsMenu、onKeyDown或onKeyUp方法中接收；

3、返回按键的消息能够在onBackPressed、onKeyDown或onKeyUp方法中接收。

@Override    public boolean onKeyDown(int keyCode, KeyEvent event) {    	switch( keyCode ){    	case KeyEvent.KEYCODE_BACK:{    		    	}    	break;    	case KeyEvent.KEYCODE_MENU:{    		    	}    	break;    	case KeyEvent.KEYCODE_SEARCH:{    		    	}    	break;    	default:{    		    	}    	break;    	}    	return super.onKeyDown(keyCode, event);    }        @Override    public boolean onKeyUp(int keyCode, KeyEvent event) {    	switch( keyCode ){    	case KeyEvent.KEYCODE_BACK:{    		    	}    	break;    	case KeyEvent.KEYCODE_MENU:{    		    	}    	break;    	case KeyEvent.KEYCODE_SEARCH:{    		    	}    	break;    	default:{    		    	}    	break;    	}    	return super.onKeyUp(keyCode, event);    }        @Override	public boolean onCreateOptionsMenu(Menu menu) {		return true;	}        @Override    public void onBackPressed() {    	super.onBackPressed();    }

    对于Home按键消息的处理，既不能通过onKeyDown、onKeyUp接收到，android也没有提供专有的方法接收按键消息，个人预计home按键算是一个app异常信息处理的后门，比方ANR后，按其他button没有比按Home按键好使。所以android为了可以提供更好的用户体验，没有提供供用户监听home按键消息的方法。

注：网上提供了各种各样监听Home按键消息的方法，但仅仅有这个比較好使。

    但办法总是有的，在每次点击Home按键时都会发出一个action为Intent.ACTION_CLOSE_SYSTEM_DIALOGS的广播，它是关闭系统Dialog的广播，我们能够通过注冊它来监听Home按键消息。我自己定义了一个home按键监听工具类。代码例如以下。使用说明參见类名上方的使用说明：

import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;/** * Home按键监听类 * 使用说明： * 1、初始化HomeListen * HomeListen homeListen = new HomeListen( this ); * homeListen.setOnHomeBtnPressListener( new setOnHomeBtnPressListener(){ * 		@Override * 		public void onHomeBtnPress( ){ * 			// 按下Home按键回调 * 		} * 		 * 		@Override * 		public void onHomeBtnLongPress( ){ * 			// 长按Home按键回调 * 		} * }); *  * 2、在onResume方法中启动HomeListen广播： * homeListen.start(); *  * 3、在onPause方法中停止HomeListen广播： * homeListen.stop( ); * */public class HomeListen {	public HomeListen(Context context) {		mContext = context;		mHomeBtnReceiver = new HomeBtnReceiver( );		mHomeBtnIntentFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);	}		public void setOnHomeBtnPressListener( OnHomeBtnPressLitener onHomeBtnPressListener ){		mOnHomeBtnPressListener = onHomeBtnPressListener;	}		public void start( ){		mContext.registerReceiver( mHomeBtnReceiver, mHomeBtnIntentFilter );	}		public void stop( ){		mContext.unregisterReceiver( mHomeBtnReceiver );	}		class HomeBtnReceiver extends BroadcastReceiver{		@Override		public void onReceive(Context context, Intent intent) {			receive( context, intent );		}	}		private void receive(Context context, Intent intent){		String action = intent.getAction();		if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {			String reason = intent.getStringExtra( "reason" );			if (reason != null) {				if( null != mOnHomeBtnPressListener ){					if( reason.equals( "homekey" ) ){						// 按Home按键						mOnHomeBtnPressListener.onHomeBtnPress( );					}else if( reason.equals( "recentapps" ) ){						// 长按Home按键						mOnHomeBtnPressListener.onHomeBtnLongPress( );					}				}			}		}	}		public interface OnHomeBtnPressLitener{		public void onHomeBtnPress( );		public void onHomeBtnLongPress( );	}		private Context mContext = null;	private IntentFilter mHomeBtnIntentFilter = null;	private OnHomeBtnPressLitener mOnHomeBtnPressListener = null;	private HomeBtnReceiver mHomeBtnReceiver = null;}

在Activity中做例如以下调用就可以：

public class HomeListenActivity extends Activity {    @Override      protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.activity_home_listen_layout);          initHomeListen( );    }        @Override    protected void onResume( ) {    	super.onResume();    	mHomeListen.start( );    }      @Override      protected void onPause() {          super.onPause();        mHomeListen.stop( );    }        private void initHomeListen( ){    	mHomeListen = new HomeListen( this );    	mHomeListen.setOnHomeBtnPressListener( new OnHomeBtnPressLitener( ) {			@Override			public void onHomeBtnPress() {				showToast( "按下Home按键！" );			}						@Override			public void onHomeBtnLongPress() {				showToast( "长按Home按键！" );			}		});    }        private void showToast( String toastInfoStr ){    	Toast.makeText( this, toastInfoStr, Toast.LENGTH_LONG ).show( );    }    private HomeListen mHomeListen = null;}

Demo程序下载地址：