如何将全局广播更改为局部广播

1)创建实例

LocalBroadcastManager localBroadcastManager = LocalBroadcastManager.getInstance(this);

2)用于注册BroadcastReceiver

取代

registerReceiver(new YourReceiver(),new IntentFilter("YourAction"));

与

localBroadcastManager.registerReceiver(new YourReceiver(),new IntentFilter("YourAction"));

3)用于发送广播信息

取代

sendBroadcast(intent);

与

localBroadcastManager.sendBroadcast(intent);

4)注销广播信息

取代

unregisterReceiver(mybroadcast);

与

localBroadcastManager.unregisterReceiver(mybroadcast);

使用LocalBroadcastManager的Kotlin版本:

请检查下面的注册代码， 发送和接收广播消息。

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // register broadcast manager
        val localBroadcastManager = LocalBroadcastManager.getInstance(this)
        localBroadcastManager.registerReceiver(receiver, IntentFilter("your_action"))
    }

    // broadcast receiver
    var receiver: BroadcastReceiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context?, intent: Intent?) {
            if (intent != null) {
                val str = intent.getStringExtra("key")
                
            }
        }
    }

    /**
     * Send broadcast method
     */
    fun sendBroadcast() {
        val intent = Intent("your_action")
        intent.putExtra("key", "Your data")
        LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
    }

    override fun onDestroy() {
        // Unregister broadcast
        LocalBroadcastManager.getInstance(this).unregisterReceiver(receiver)
        super.onDestroy()
    }

}

我还是要回答这个问题。以防有人需要。

ReceiverActivity.java

一个监视名为“custom-event-name”的事件通知的活动。

@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

第二个活动发送/广播通知。

@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，每次按钮都是R.id。button_send被点击，Intent被广播并被ReceiverActivity中的mMessageReceiver接收。

调试输出应该是这样的:

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! 

在Eclipse中，最终我不得不通过右键单击我的项目并选择添加兼容性/支持库:

Android工具->添加支持库

一旦添加了它，我就可以在代码中使用LocalBroadcastManager类了。

当你玩够了LocalBroadcastReceiver的时候，我会建议你试试Green Robot的EventBus——你一定会意识到它与LBR的区别和有用性。更少的代码，可定制关于接收者的线程(UI/Bg)，检查接收者的可用性，粘性事件，事件可以用作数据传递等。

我们也可以使用接口相同的broadcastManger在这里我分享broadcastManager的测试代码，但通过接口。

首先，创建如下界面:

public interface MyInterface {
     void GetName(String name);
}

2-这是第一个需要实现的类

public class First implements MyInterface{

    MyInterface interfc;    
    public static void main(String[] args) {
      First f=new First();      
      Second s=new Second();
      f.initIterface(s);
      f.GetName("Paddy");
  }
  private void initIterface(MyInterface interfc){
    this.interfc=interfc;
  }
  public void GetName(String name) {
    System.out.println("first "+name);
    interfc.GetName(name);  
  }
}

3-这里是实现相同接口的第二个类，其方法自动调用

public class Second implements MyInterface{
   public void GetName(String name) {
     System.out.println("Second"+name);
   }
}

因此，通过这种方法，我们可以使用与broadcastManager功能相同的接口。