Android一句話區分sendBroadcast與sendStickyBroadcast

小例實現步驟：

①.在MainActivity裡面發送兩種類型的廣播：sendBroadcast和sendStickyBroacat。

②在ReceverActivity裡面通過BroadcastReceiver來接收這兩個訊息，這裡是通過代碼來註冊Recevier而不是在Manifest裡面註冊的。

③結論：通過sendBroadcast中發出的intent在ReceverActivity不處於onResume狀態是無法接受到的，即使後面再次使其處於該狀態也無法接受到。而sendStickyBroadcast發出的Intent當ReceverActivity重新處於onResume狀態之後就能重新接受到其Intent。這就是the Intent will be held to be re-broadcast
to future receivers這句話的表現。就是說sendStickyBroadcast發出的最後一個Intent會被保留，下次當Recevier處於活躍的時候，又會接受到它。

④在wifi中就是發送的粘性廣播。

 

下面是兩個類的代碼部分。

MainActivity：

public class MainActivity extends Activity {       Button btnSendi;       Button btnSends;       Button btnStart;       Context mContext;       /** Called when the activity is first created. */      @Override      public void onCreate(Bundle savedInstanceState) {           super.onCreate(savedInstanceState);           setContentView(R.layout.main);           btnSendi=(Button) findViewById(R.id.sendi);           btnSends=(Button) findViewById(R.id.sends);           btnStart=(Button) findViewById(R.id.start);           mContext=getApplicationContext();           btnSendi.setOnClickListener(new OnClickListener(){                 @Override              public void onClick(View v) {                   // TODO Auto-generated method stub                   Intent intent = new Intent();                   intent.setAction("com.android.my.action");                   intent.setFlags(1);                   mContext.sendBroadcast(intent);               }                          });                      btnStart.setOnClickListener(new OnClickListener(){                 @Override              public void onClick(View v) {                   // TODO Auto-generated method stub                   Intent intent = new Intent(MainActivity.this,ReceiverActivity.class);                                     startActivity(intent);               }                          });                      btnSends.setOnClickListener(new OnClickListener(){                 @Override              public void onClick(View v) {                   // TODO Auto-generated method stub                   Intent intent = new Intent();                   intent.setAction("com.android.my.action.sticky");                   intent.setFlags(2);                   mContext.sendStickyBroadcast(intent);               }                          });       }   }  

ReceiverActivity ：

public class ReceiverActivity extends Activity {        private IntentFilter mIntentFilter;              /** Called when the activity is first created. */      @Override      public void onCreate(Bundle savedInstanceState) {           super.onCreate(savedInstanceState);           setContentView(R.layout.main);           mIntentFilter = new IntentFilter();           mIntentFilter.addAction("com.android.my.action");           mIntentFilter.addAction("com.android.my.action.sticky");                        }       private BroadcastReceiver mReceiver = new BroadcastReceiver() {             @Override          public void onReceive(Context context, Intent intent) {               final String action = intent.getAction();               System.out.println("action"+action);                          }       };              @Override      protected void onResume() {           // TODO Auto-generated method stub           super.onResume();           registerReceiver(mReceiver, mIntentFilter);       }              @Override      protected void onPause() {           // TODO Auto-generated method stub           super.onPause();           unregisterReceiver(mReceiver);       }                 }