Android 本地广播

正常的广播是全局广播，所有的应用都可以接收到，如果我们用其发送一些数据，容易被其他应用获取，引起安全问题。其他应用也可以发送广播，被我们的应用接收，也可能导致安全问题。

所以引入了本地广播机制

　使用LocalBroadcastManager来管理广播：

1. 调用LocalBroadcastManager.getInstance()来获得实例
2. 调用xx.registerReceiver()来注册广播
3. 调用xx.sendBroadcast()发送广播
4. 调用xx.unregisterReceiver()取消注册

代码如下：

public class LocalReciverActivity extends AppCompatActivity {
    private final static String MY_ACTION = "CON.DU.TEST";
    private LocalBroadcastManager localBroadcastManager;
    private TestLocalReciver reciver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_local_reciver);
        reciver = new TestLocalReciver();
        localBroadcastManager = LocalBroadcastManager.getInstance(this);
        IntentFilter intentFilter = new IntentFilter(MY_ACTION);
        localBroadcastManager.registerReceiver(reciver , intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        localBroadcastManager.unregisterReceiver(reciver);
    }

    public void send(View view) {
        Intent intent = new Intent(MY_ACTION);
        localBroadcastManager.sendBroadcast(intent);
    }

    class TestLocalReciver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context , "接收到广播" , Toast.LENGTH_SHORT).show();
        }
    }

}