Android基础复习之广播Broadcast

Android广播知识复习

• 作者：朱红喜

1.广播分类

• 按通信方式分类
  • 标准广播 （normal broadcast）
  • 有序广播 （ordered broadcast）
• 按广播区域分类
  • 全局广播
  • 本地广播（Localbrodcast）

1. 标准广播：完全异步的广播，广播发出后每一个广播接收器都会同一时刻接收到这条广播信息，无法被拦截。
2. 有序广播：一种同步的广播，同一时刻只能由一个接收器能够接收到这条广播，接收器有顺序优先级，广播可以截断
3. 全局广播：所有的应用都可以收到的广播
4. 本地广播：只能够被本应用内的接收器接收到

2.动态注册广播接收器

private IntentFilter intentFilter;
private Customreceiver  mReceiver;

@Override
protected void onCreate(Bundle saveInstanceState){
	super.onCreate(saveInstanceState);
	setContentView(R.layout.activity_main);
	intentFilter = new IntentFilter();
	intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
	mReceiver= new Customreceiver();
	registerReceiver(mReceiver,intentFilter);
} 

@Override
protected void onDestroy(){
	super.onDestroy();
	unregisterReceiver(mReceiver);
}
class Customreceiver extends broadcastReceiver{
	@Override
	public void onReceive(Context context,Intent intent){
		//你的逻辑代码
	}
}

3.静态注册广播(manifest文件中)

<receiver
android：name=".Customreceiver"
android:enabled="true" 启用这个广播
android:exported="true">  是否允许接收本程序外的广播
<intent-filter>
	<action android:name="你需要的action"/>
</intent-filter>
</receiver>

4.发送广播

• 发送标准广播

Intent intent = new Intent("你的广播的action")
sendbroadcast(intent);

• 发送有序广播

Intent intent = new Intent("你的广播的action")
sendOrderedbroadcast(intent);

5.使用本地广播

private IntentFilter intentFilter;
private Customreceiver  mReceiver;
private LocalbroadcastManager localbroadcastManager

@Override
protected void onCreate(Bundle saveInstanceState){
	super.onCreate(saveInstanceState);
	setContentView(R.layout.activity_main);
	
	localbroadcastManager = LocalbroadcastManager.getInstance(this);
	intentFilter = new IntentFilter();
	intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
	mReceiver= new Customreceiver();
	localbroadcastManager.registerReceiver(mReceiver,intentFilter);
} 

@Override
protected void onDestroy(){
	super.onDestroy();
	localbroadcastManager.unregisterReceiver(mReceiver);
}
class Customreceiver extends broadcastReceiver{
	@Override
	public void onReceive(Context context,Intent intent){
		//你的逻辑代码
	}
}

发送广播

private LocalbroadcastManager localbroadcastManager
...
Intent intent = new Intent("你的广播的action")
localbroadcastManager.sendbroadcast(intent);
...

6.不要滥用广播