Android 監聽Home key

Android 應用對於Home鍵的監聽不是那麼容易,因爲Home鍵可以將程序退出放在後臺,所以這個事件是直接分發給系統,系統接收到之後做相應處理,Home鍵的事件不是直接傳遞到應用裏面.所以不可以像在應用監聽Back鍵那樣（override Activity的 onkeydown）的方法監聽Home.

下面提供一種監聽Home的實現方式：

public class HomeWatcher {
   
   static final String TAG = "HomeWatcher";
   private Context mContext;
   private IntentFilter mFilter;
   private OnHomePressedListener mListener;
   
   private InnerReceiver mReceiver;
   
   public interface OnHomePressedListener
   {
      public void onHomePressed();
      public void onHomeLongPressed();
   }
   
   public HomeWatcher(Context context)
   {
      mContext = context;
      mFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
   }

   public void setOnHomePressedListener(OnHomePressedListener listener)
   {
      mListener = listener;
      mReceiver = new InnerReceiver();
   }
   
   public void startWatch()
   {
      if(mReceiver != null)
      {
         mContext.registerReceiver(mReceiver, mFilter);
      }
   }
   
   public void stopWatch()
   {
      if(mReceiver != null)
      {
         mContext.unregisterReceiver(mReceiver);
      }
   }
   
   class InnerReceiver extends BroadcastReceiver
   {
      final String SYSTEM_DIALOG_REASON_KEY = "reason"; 
        final String SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS = "globalactions"; 
        final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps"; 
        final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";
        
        @Override 
        public void onReceive(Context context, Intent intent) {
         Log.d(TAG,"home key");
            String action = intent.getAction(); 
            if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) { 
                String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY); 
                if (reason != null) { 
                    Log.e(TAG, "action:" + action + ",reason:" + reason); 
                    if (mListener != null) { 
                        if (reason.equals(SYSTEM_DIALOG_REASON_HOME_KEY)) { 
                            // 短按home鍵 
                            mListener.onHomePressed(); 
                        } else if (reason 
                                .equals(SYSTEM_DIALOG_REASON_RECENT_APPS)) { 
                            // 長按home鍵 
                            mListener.onHomeLongPressed(); 
                        } 
                    } 
                } 
            } 
        } 
      
   }
   
   
   
}

使用方式：

HomeWatcher homeWatcher = new HomeWatcher(mContext);

homeWatcher.setOnHomePressedListener(new HomeWatcher.OnHomePressedListener() { @Override public void onHomePressed() { Log.d(TAG, "onHomePressed"); } @Override public void onHomeLongPressed() { Log.d(TAG, "onHomeLongPressed"); }});homeWatcher.startWatch();

結語，

採用動態註冊廣播的方式，經測這是一種行之有效的監聽Home key 辦法。