android - 如何使用本地广播管理器？

Question

如何使用/定位 LocalBroadcastManager，如 google docs 中所述和 Service broadcast doc ?

我尝试用谷歌搜索，但没有可用的代码？

文件说如果我想在我的应用程序的进程中进行内部广播，我应该使用它，但我不知道在哪里寻找它。

任何帮助/评论？

更新:我知道如何使用广播，但不知道如何在我的项目中使用 LocalBroadcastManager。

Answer 1

无论如何我都会回答这个问题。以防万一有人需要。

ReceiverActivity.java

监视名为 "custom-event-name" 的事件通知的 Activity .

@Override
public void onCreate(Bundle savedInstanceState) {

  ...

  // Register to receive messages.
  // We are registering an observer (mMessageReceiver) to receive Intents
  // with actions named "custom-event-name".
  LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
      new IntentFilter("custom-event-name"));
}

// Our handler for received Intents. This will be called whenever an Intent
// with an action named "custom-event-name" is broadcasted.
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
  @Override
  public void onReceive(Context context, Intent intent) {
    // Get extra data included in the Intent
    String message = intent.getStringExtra("message");
    Log.d("receiver", "Got message: " + message);
  }
};

@Override
protected void onDestroy() {
  // Unregister since the activity is about to be closed.
  LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
  super.onDestroy();
}

SenderActivity.java

发送/广播通知的第二个 Activity 。

@Override
public void onCreate(Bundle savedInstanceState) {

  ...

  // Every time a button is clicked, we want to broadcast a notification.
  findViewById(R.id.button_send).setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
      sendMessage();
    }
  });
}

// Send an Intent with an action named "custom-event-name". The Intent sent should 
// be received by the ReceiverActivity.
private void sendMessage() {
  Log.d("sender", "Broadcasting message");
  Intent intent = new Intent("custom-event-name");
  // You can also include some extra data.
  intent.putExtra("message", "This is my message!");
  LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

使用上面的代码，每次按钮 R.id.button_send被点击，一个 Intent 被广播并被 mMessageReceiver 接收在 ReceiverActivity .

调试输出应如下所示:

01-16 10:35:42.413: D/sender(356): Broadcasting message
01-16 10:35:42.421: D/receiver(356): Got message: This is my message!