如何在主活动中监听BroadcastReceiver？

public class MyBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals("com.example.MY_CUSTOM_ACTION")) {
            // 处理自定义广播消息
            Toast.makeText(context, "Custom Broadcast Received", Toast.LENGTH_SHORT).show();
        }
    }
}

public class MainActivity extends AppCompatActivity {
    private MyBroadcastReceiver myBroadcastReceiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 初始化 BroadcastReceiver
        myBroadcastReceiver = new MyBroadcastReceiver();

        // 创建 IntentFilter 并添加自定义动作
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.example.MY_CUSTOM_ACTION");

        // 动态注册 BroadcastReceiver
        registerReceiver(myBroadcastReceiver, intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 取消注册 BroadcastReceiver，防止内存泄漏
        unregisterReceiver(myBroadcastReceiver);
    }
}

Intent intent = new Intent("com.example.MY_CUSTOM_ACTION");
sendBroadcast(intent);

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>