Android四大组件之broadcast广播使用讲解

public class MyBroadcast extends BroadcastReceiver {
    @Override
    // 当广播接收者接收广播成功，此方法会自动回调执行，在该方法中实现广播接收者的相关操作
    public void onReceive(Context context, Intent intent) {
    }
}

<receiver
   android:name=".utils.MyBroadcast"
   android:enabled="true"
   android:exported="true">
   <intent-filter>
   	<action>cn.com.hello</action> 
   </intent-filter>
</receiver>

<receiver
   android:name=".utils.MyBroadcast"
   android:enabled="true"
   android:exported="true">
</receiver>

public class BroadcastReceiverActivity extends AppCompatActivity {
    private MyBroadcast myBroadcast;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_broadcast_receiver);
        // 创建广播接收者对象
        myBroadcast = new MyBroadcast();
        String action = "cn.com.hello"
        // 创建意图过滤器
        IntentFilter intentFilter = new IntentFilter();
        // 设置要过滤的广播
        intentFilter.addAction(action );
        // 注册广播接收者
        registerReceiver(myBroadcast,intentFilter);
    }
    // 广播接收者是稀缺资源，使用结束要注销，可以在app销毁的阶段进行注销
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(myBroadcast);
    }
}

btn = findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {
      // 发送一次广播
      Intent intent = new Intent();
      intent.putExtra("info","hello,who are you ?");
      // 设置广播的action，相当于广播的名称
      String action = "cn.com.hello"
      intent.setAction(action);
      // 发送广播，广播会发送到信息中心，由信息中心负责找到这个广播的订阅者并将广播的意图传过去
      // 无序广播
		 sendBroadcast(intent);
  }
});

public class MyBroadcast extends BroadcastReceiver {
    @Override
    // 当广播接收者接收广播成功，此方法会自动回调执行
    public void onReceive(Context context, Intent intent) {
        String msg = intent.getStringExtra("info");
			 Log.v("msg","接收到了广播信息！");
    }
}

myBroadcast = new MyBroadcast();
String action = "cn.com.hello"
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(action); 
registerReceiver(myBroadcast,intentFilter);

Intent intent = new Intent();
intent.putExtra("info","hello,who are you ?");
String action = "cn.com.hello"
intent.setAction(action);
// 有序广播
sendOrderedBroadcast(intent,null);

public class MyBroadcast extends BroadcastReceiver {
    @Override
    // 当广播接收者接收广播成功，此方法会自动回调执行
    public void onReceive(Context context, Intent intent) {
        String msg = intent.getStringExtra("info");
			 Log.v("msg","接收到了广播信息！");
			 // 截断广播的发送，之后的广播接收者就接收不到广播了
        abortBroadcast();
    }
}

myBroadcast = new MyBroadcast();
String action = "cn.com.hello"
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(action); 
// 设置优先级
intentFilter.setPriority(8);
// 注册广播接收者
registerReceiver(myBroadcast,intentFilter);