一、使用註冊廣播監聽home鍵、多工鍵

class InnerRecevier extends BroadcastReceiver {

  final String SYSTEM_DIALOG_REASON_KEY = "reason";
 
  final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps";
 
  final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";
 
  @Override
  public void onReceive(Context context, Intent intent) {
   String action 
 
= intent.getAction();
   if (Intent.ACTION_CLOSE_SYSTEM_DIALOGS.equals(action)) {
    String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);
    if (reason != null) {
     if (reason.equals(SYSTEM_DIALOG_REASON_HOME_KEY)) {
      Toast.makeText(MainActivity.this, "Home鍵被監聽", Toast.LENGTH_SHORT).show();
     } 
 
else if (reason.equals(SYSTEM_DIALOG_REASON_RECENT_APPS)) {
      Toast.makeText(MainActivity.this, "多工鍵被監聽", Toast.LENGTH_SHORT).show();
     }
    }
   }
  }
｝

在Activity中的onCreate()方法中註冊廣播，程式碼如下：

@Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 
  
 
//建立廣播
  InnerRecevier innerReceiver = new InnerRecevier();
  //動態註冊廣播
  IntentFilter intentFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
  //啟動廣播
  registerReceiver(innerReceiver, intentFilter);
 }