音乐播放器widget 补充-优快云博客

本文链接：https://blog.youkuaiyun.com/iteye_6288/article/details/81822772

本文介绍了音乐播放器Widget中采用的BroadcastReceiver和Bundle复用技术。通过具体实例展示了如何利用这两种方式在组件间传递消息，包括注册监听器、发送广播及解析数据的过程。

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音乐播放器widget 补充

[功能]

在音乐播放器widget 前传后传有一些没讲清楚所以打算再开辟专门说一下

1. Bundle 复用

2. BroadcastReceiver 复用

[前提]

1. 现有一BroadcastReceiver：class MessageListenerHelper extends BroadcastReceiver 实现如下：

public class MessageListenerHelper extends BroadcastReceiver {
		Context context;
		
		MessageListenerHelper listener;
		//construct 
		public MessageListenerHelper(Context c){
			context = c;
			
			//to instance it
			listener = this;
		}
		
		public void registerAction(String action){
			IntentFilter filter = new IntentFilter();
			filter.addAction(action);
			
			context.registerReceiver(listener,filter);
		}
		
		@Override
		public void onReceive(Context arg0, Intent arg1) {
			// TODO Auto-generated method stub

		}
		
	}

写道

补充：

其 onReceive() 没有实现将在具体情况中分别实现之

以下就2点予以说明：

[Bundle 复用]

1. 注册MessageListenerHelper

MessageListenerHelper listener = new MessageListenerHelper(this);


listener.registerAction("Broadcast_MessageListwener");

2. 发生某Broadcast

public void sendMessageText(String s){
    	Intent i = new Intent(BroadcastColumn.BROADCAST_TaskB);
    	
    	Bundle b = new Bundle();
    	b.putString("Message_Text", s);
    	
    	i.putExtras(b);
    	sendBroadcast(i);
    }

3. 实现onReceive() 并对具体消息做判断

public void onReceive(Context arg0, Intent arg1) {
			// TODO Auto-generated method stub
			
			
Bundle b = arg1.getExtras();
			
if(b.containsKey("Message_Text")){
				String string = b.getString("Message_Text");
				Log.d("TAG",string);
			}

		}

4. 如此就实现了Bundle 复用

[Broadcast 复用]

1. 注册MessageListenerHelper

MessageListenerHelper listener = new MessageListenerHelper(this);

listener.registerAction("Broadcast_MessageListener_1");
		

MessageListenerHelper listener2 = new MessageListenerHelper(this);

listener2.registerAction(Broadcast_MessageListener_2);

2. 发生某Broadca

public void sendMessage1(String b,String key, String value){
    	Intent i = new Intent(b);
    	
    	Bundle b = new Bundle();
    	b.putString(key, value);
    	
    	i.putExtras(b);
    	sendBroadcast(i);
    }

3. 实现onReceive() 并对具体Broadcast 做判断

public void onReceive(Context arg0, Intent arg1) {
			// TODO Auto-generated method stub
			
if(arg1.getAction().endsWith("Broadcast_MessageListener_1")){


Bundle b = arg1.getExtras();
				
if(b.containsKey("Message_Text_1")){

String string = b.getString("Message_Text_1");


Log.d("TAG",string);
				}
}
else if(arg1.getAction().endsWith("Broadcast_MessageListener_2")){


Bundle b = arg1.getExtras();
				
if(b.containsKey("Message_Text_2")){


String string = b.getString("Message_Text_2");


Log.d("TAG",string);
				}
			}
			
		}

4. 此为Broadcast 复用

补充：

1. 其实除了在widget中必须用 Broadcast复用外二者都可以使用具体用那个视情况而定

2. 因为Broadcast复用中需要new 2 次所以推荐尽量用 Bundle 复用仅限个人意见