一、概念
系统广播可以被其他任何的应用程序接收到,同时也可以接受到其他任何应用程序发出的广播,存在一定的安全性问题。
本地广播只能在应用程序内部传递,广播接收器也只能接受来自本应用程序发出的广播。
二、本地广播用法
本地广播使用LocalBroadcastManager进行管理。本地广播无法通过静态注册的方式来接受。
public class MainActivity extends Activity {
private IntentFilter intentFilter; private LocalReceiver localReceiver; private LocalBroadcastManager localBroadcastManager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); localBroadcastManager = LocalBroadcastManager.getInstance(this); // 获取实例 Button button = (Button) findViewById(R.id.button); button.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent("com.example.broadcasttest.LOCAL_BROADCAST"); localBroadcastManager.sendBroadcast(intent); // 发送本地广播 } }); intentFilter = new IntentFilter(); intentFilter.addAction("com.example.broadcasttest.LOCAL_BROADCAST"); localReceiver = new LocalReceiver(); localBroadcastManager.registerReceiver(localReceiver, intentFilter); // 注册本地广播监听器 } @Override protected void onDestroy() { super.onDestroy();localBroadcastManager.unregisterReceiver(localReceiver);
} class LocalReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { Toast.makeText(context, "received local broadcast", Toast.LENGTH_SHORT).show(); } } }