The application called an interface that was marshalled for a different thread - Windows Store App

Question

So, first I have read a ton of threads on this particular problem and I still do not understand how to fix it. Basically, I am trying to communicate with a websocket and store the message received in an observable collection that is bound to a listview. I know that I am getting a response back properly from the socket, but when it tries to add it to the observable collection it gives me the following error:

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

I've read some information on "dispatch" as well as some other things, but I am just massively confused! Here is my code:

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

    }

And this is the binding:

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

How do I make the error go away while still binding to the observable collection for my listview?

Answer 1

This solved my issue:

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