应用程序调用了为不同线程编组的接口 - Windows Store App

Question

所以，首先我已经阅读了大量关于这个特定问题的线程，但我仍然不明白如何解决它。基本上，我正在尝试与 websocket 通信并将收到的消息存储在绑定到列表视图的可观察集合中。我知道我从套接字正确地得到了响应，但是当它尝试将它添加到可观察集合中时，它给了我以下错误：

The application called an interface that was marshalled for a different thread. (Exception from HRESULT: 0x8001010E (RPC_E_WRONG_THREAD))

我已经阅读了一些关于“调度”的信息以及其他一些信息，但我非常困惑！这是我的代码：

public ObservableCollection<string> messageList  { get; set; }
private void MessageReceived(MessageWebSocket sender, MessageWebSocketMessageReceivedEventArgs args)
    {
        string read = "";
        try
        {
            using (DataReader reader = args.GetDataReader())
            {
                reader.UnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding.Utf8;
                read = reader.ReadString(reader.UnconsumedBufferLength);
            }
        }
        catch (Exception ex) // For debugging
        {
            WebErrorStatus status = WebSocketError.GetStatus(ex.GetBaseException().HResult);
            // Add your specific error-handling code here.
        }


        if (read != "")
           messageList.Add(read); // this is where I get the error

    }

这是绑定：

protected override async void OnNavigatedTo(NavigationEventArgs e)
{
    //await Authenticate();
    Gameboard.DataContext = Game.GameDetails.Singleton;
    lstHighScores.ItemsSource = sendInfo.messageList;
}

如何在仍然绑定到我的列表视图的可观察集合的同时使错误消失？

Answer 1

这解决了我的问题：

Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
() =>
    {
        // Your UI update code goes here!
    }
);

Correct way to get the CoreDispatcher in a Windows Store app

Answer 2

尝试替换

messageList.Add(read); 

与

Dispatcher.Invoke((Action)(() => messageList.Add(read)));

如果您是从 Window 类外部调用，请尝试：

Application.Current.Dispatcher.Invoke((Action)(() => messageList.Add(read)));

Answer 3

对基于任务的异步方法稍作修改，但不会等待此处的代码。

await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
() =>
{
    // Your UI update code goes here!
}
).AsTask();

此代码将等待，并允许您返回一个值：

    private async static Task<string> GetPin()
    {
        var taskCompletionSource = new TaskCompletionSource<string>();

        CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
        async () =>
        {
            var pin = await UI.GetPin();
            taskCompletionSource.SetResult(pin);
        }
        );

        return await taskCompletionSource.Task;
    }

在 Android 上：

    private async Task<string> GetPin()
    {
        var taskCompletionSource = new TaskCompletionSource<string>();

        RunOnUiThread(async () =>
        {
            var pin = await UI.GetPin();
            taskCompletionSource.SetResult(pin);
        });

        return await taskCompletionSource.Task;
    }

Answer 4

也许这不是一个“好”的做法，但它确实有效。我从 webSocket 向 mainBody 实例留言，在那里我有一个定时阅读器...

public class C_AUTHORIZATION
{
    public Observer3.A_MainPage_cl parentPageInstance; //еще одни экземпляр родителя
    public WebSocket x_Websocket; 
    private string payload = "";
    private DateTime nowMoment = DateTime.Now;
    public void GET_AUTHORIZED()
    {
       bitfinex_Websocket= new WebSocket("wss://*****.com/ws/2");

        var apiKey = "";
        var apiSecret = "";
        DateTime nowMoment = DateTime.Now;            

        payload = "{}";            

        x_Websocket.Opened += new EventHandler(websocket_Opened);                                                         
       x_Websocket.Closed += new EventHandler(websocket_Closed);  
    }
    
    void websocket_Opened(object sender, EventArgs e)
    {
        x_Websocket.Send(payload);
        parentPageInstance.F_messager(payload);
    }
    
    void websocket_Closed(object sender, EventArgs e)
    {
        parentPageInstance.F_messager("L106 websocket_Closed!");
        GET_AUTHORIZED();  
    }
   

}

public sealed partial class A_MainPage_cl : Page
{      
    DispatcherTimer ChartsRedrawerTimer;
    public bool HeartBeat = true;
   
    private string Message;        
    public A_MainPage_cl()
    {
       this.InitializeComponent();
      
        ChartsRedrawerTimer = new DispatcherTimer() { Interval = new TimeSpan(0, 0, 0, 0, 100) }; 
        ChartsRedrawerTimer.Tick += Messager_Timer;
        ChartsRedrawerTimer.Start();

        
    }        
         
    private void Messager_Timer(object sender, object e)
    {            
        if(Message !=null) // 
        {
            F_WriteLine(Message);
            Message = null; //  

        } 
    }
    public void F_messager(string message) // 
    { 
        Message = message; 
    }