在Xamarin Android上取消注册后，BroadcastReciever仍然有效

Question

我正在开发Xamarin Forms应用程序，但是当我改变网络状态时，我想使用BroadcastReciever。这是我的代码：

    protected override void OnStart()
    {
        IsVisible = true;
        base.OnStart();
    }


    protected override void OnPause()
    {
        _receiver = new InternetBroadcastReceiver();
        LocalBroadcastManager.GetInstance(this).UnregisterReceiver(_receiver);//doesn't work
        IsVisible = false;
        Debug.WriteLine("pause");
        base.OnPause();
    }


    protected override void OnResume()
    {
        IsVisible = true;
        Debug.WriteLine("resume");
        SendReceiver();
        base.OnResume();
    }


    private void SendReceiver()
    {
        LocalBroadcastManager.GetInstance(this).RegisterReceiver(_receiver, new IntentFilter(Android.Net.ConnectivityManager.ConnectivityAction));
        var intent = new Intent(this, typeof(InternetBroadcastReceiver));
        SendBroadcast(intent);//work only with global
    }

是的，奇怪的是，SendBroadcast方法只有在我从全球接收者那里调用它时才有效。我不知道，这是一个什么问题。也许这是Xamarin Forms的问题，或者我做错了什么？接收者我只注册代码，没有清单