Android的广播机制方便了开发者接收系统及其他APP发送的广播（开机，电池电量改变等，那么如何自定义一个广播呢？下面来说说自定义广播的流程

• ****第一步****
  先设置好一个独一无二的action（一个字符串），发送和接收广播都要依靠这个action，以下为例：
  public static final String ACTION_MEMEDA = "com.shijianan.demo.memeda";

• ****第二步****
  新建BroadcastReceiver子类，重写onReceive方法
  public class MemedaReceiver extends BroadcastReceiver {
  public static final String ACTION_MEMEDA = "com.shijianan.demo.memeda";
  public static final String EXTRA_MEMEDA = "memeda";

      @Override
      public void onReceive(Context context, Intent intent) {
            //一旦接收到通知，并且通知携带数据的话就吐司出来
            if(intent!=null&&intent.hasExtra(EXTRA_MEMEDA)){
                Toast.makeText(context, intent.getStringExtra(EXTRA_MEMEDA), Toast.LENGTH_SHORT).show();
            }
       }
  }
  

• ****第三步****
  注册并使用接收器
  1，动态注册

  public class BroadcastActivity extends AppCompatActivity {
  
      private MemedaReceiver memedaReceiver;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_broadcast);
            initView();
            registerReceiver();
      }
  
      private void initView(){
            findViewById(R.id.custom).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //发送一个通知
                    Intent intent = new Intent(MemedaReceiver.ACTION_MEMEDA);
                    intent.putExtra(MemedaReceiver.EXTRA_MEMEDA,"memeda");
                    sendBroadcast(intent);
                }
            });
        }
  
        private void registerReceiver(){
            //初始化广播接收器对象，注册广播
            memedaReceiver = new MemedaReceiver();
            //这里的action就是一开始定义的那个action
            IntentFilter intentFilter = new IntentFilter(MemedaReceiver.ACTION_MEMEDA);
            registerReceiver(memedaReceiver,intentFilter);
        }
  
       @Override
        protected void onStart() {
            super.onStart();
            //也可以在这里注册
        }
  
        @Override
        protected void onStop() {
            super.onStop();
            //如果在onStart（）中注册在这里记得反注册
        }
  
        @Override
        protected void onDestroy() {
            super.onDestroy();
            //反注册
            unregisterReceiver(memedaReceiver);
        }
    }
  

2，静态注册

• AndroidManifest中Application节点下添加如下代码
  <receiver android:name=".broadcastreceive.MemedaReceiver">
  <intent-filter>
  
  <action android:name="com.shijianan.demo.memeda"/>
  </intent-filter>
  </receiver>
• 要发送一个通知则如下所示
  //MemedaReceiver.ACTION_MEMEDA的值等于刚才的action的值
  Intent intent = new Intent(MemedaReceiver.ACTION_MEMEDA);
  intent.putExtra(MemedaReceiver.EXTRA_MEMEDA,"memeda");
  sendBroadcast(intent);