//首先新建一个继承自BroadcastReceiver的广播监听类
class StartActiviryReceiver extends BroadcastReceiver {
        public final static String intentKey = "startTestActivity";
        @Override
        public void onReceive(Context context, Intent intent) {
            Intent t = new Intent(MyActivity.this, TestActivity.class);
            startActivity(t);
        }
    }

//注册private StartActiviryReceiver startActiviryReceiver;
@Override
    protected void onResume() {
        super.onResume();

        //注册监听广播
        startActiviryReceiver = new StartActiviryReceiver();
        registerReceiver(startActiviryReceiver, new IntentFilter(startActiviryReceiver.intentKey));

    }

在完成某件事之后，进行广播通知

Intent intent = new Intent(StartActiviryReceiver.intentKey);
sendBroadcast(intent);

Android -- BroadCastReceiver的简单使用