Winforms或WPF上托管的TCP WCF服务挂起

Question

I am getting an error in Tcp Wcf Service hosted on winforms or WPF. The service either hangs or throws "Thread Exited" error.

The same code works fine in a console application.

Thanks.

Server:

  namespace WCFService { //interface declarations just like the client but the callback //decleration is a little different [ServiceContract] interface IMessageCallback { [OperationContract(IsOneWay = true)] void OnMessageAdded(string message, DateTime timestamp); } //This is a little different than the client // in that we need to state the SessionMode as required or it will default to "notAllowed" [ServiceContract(CallbackContract = typeof(IMessageCallback), SessionMode = SessionMode.Required)] public interface IMessage { [OperationContract] void AddMessage(string message); [OperationContract] bool Subscribe(); [OperationContract] bool Unsubscribe(); } [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)] class RCRServer : IMessage { private static List<IMessageCallback> subscribers = new List<IMessageCallback>(); public ServiceHost host = null; public void Connect() { //I'm doing this next part progromatically instead of in app.cfg // because I think it makes it easier to understand (and xml is stupid) host = new ServiceHost(typeof(RCRServer), new Uri("net.tcp://localhost:8000")); //notice the NetTcpBinding? This allows programs instead of web stuff // to communicate with each other host.AddServiceEndpoint(typeof(IMessage), new NetTcpBinding(), "ISubscribe"); try { host.Open(); Console.WriteLine("Successfully opened port 8000."); //Console.ReadLine(); //host.Close(); } catch (Exception e) { Console.WriteLine(e.Message); } } public bool Subscribe() { try { //Get the hashCode of the connecting app and store it as a connection IMessageCallback callback = OperationContext.Current.GetCallbackChannel<IMessageCallback>(); if (!subscribers.Contains(callback)) subscribers.Add(callback); return true; } catch (Exception e) { Console.WriteLine(e.Message); return false; } } public bool Unsubscribe() { try { //remove any connection that is leaving IMessageCallback callback = OperationContext.Current.GetCallbackChannel<IMessageCallback>(); if (subscribers.Contains(callback)) subscribers.Remove(callback); return true; } catch { return false; } } public void AddMessage(String message) { //Console.WriteLine("Calling OnMessageAdded on callback"); //foreach (Subscriber s in subscribers.Values.ToList()) //{ } try { Console.WriteLine("Clients connected to service " + subscribers.Count.ToString()); IMessageCallback callback = OperationContext.Current.GetCallbackChannel<IMessageCallback>(); callback.OnMessageAdded(message, DateTime.Now); } catch (Exception ex) { Console.WriteLine(ex.Message); } //Go through the list of connections and call their callback funciton //subscribers.ForEach(delegate (IMessageCallback callback) //{ // //System.Threading.Thread.Sleep(1000); // if (((ICommunicationObject)callback).State == CommunicationState.Opened) // { // Console.WriteLine("Clients connected to service " + subscribers.Count.ToString()); // callback.OnMessageAdded(message, DateTime.Now); // } // else // { // subscribers.Remove(callback); // } //}); } } } Client: namespace WCFClient { //These are the interface declerations for the client [ServiceContract] interface IMessageCallback { //This is the callback interface decleration for the client [OperationContract(IsOneWay = true)] void OnMessageAdded(string message, DateTime timestamp); } [ServiceContract(CallbackContract = typeof(IMessageCallback))] public interface IMessage { //these are the interface decleratons for the server. [OperationContract] void AddMessage(string message); [OperationContract] bool Subscribe(); [OperationContract] bool Unsubscribe(); } class RCRProxy : IMessageCallback, IDisposable { IMessage pipeProxy = null; //MainWindow mainwindow = new MainWindow(); //public RCRProxy(MainWindow main) //{ // mainwindow = main; //} public bool Connect() { //note the "DuplexChannelFactory". This is necessary for Callbacks. // A regular "ChannelFactory" won't work with callbacks. DuplexChannelFactory<IMessage> pipeFactory = new DuplexChannelFactory<IMessage>( new InstanceContext(this), new NetTcpBinding(), new EndpointAddress("net.tcp://localhost:8000/ISubscribe")); try { //Open the channel to the server pipeProxy = pipeFactory.CreateChannel(); //Now tell the server who is connecting pipeProxy.Subscribe(); return true; } catch (Exception e) { Console.WriteLine(e.Message); return false; } } public void Close() { pipeProxy.Unsubscribe(); } //This function sends a string to the server so that it can broadcast // it to all other clients that have called Subscribe(). public string SendMessage(string message) { try { System.Threading.Thread.Sleep(1000); pipeProxy.AddMessage(message); return "sent >>>> " + message; } catch (Exception e) { return e.Message; } } //This is the function that the SERVER will call public void OnMessageAdded(string message, DateTime timestamp) { //Console.WriteLine(message + ": " + timestamp.ToString("hh:mm:ss")); // mainwindow.txtblkStatus.Text = message + ": " + timestamp.ToString("hh:mm:ss"); } //We need to tell the server that we are leaving public void Dispose() { pipeProxy.Unsubscribe(); } } } namespace StockTickerClient { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> /// public class DataItem { public string Symbol { get; set; } public string Series { get; set; } public float? AskPrice { get; set; } public float? BidPrice { get; set; } public float? LTP { get; set; } public int? Volume { get; set; } public string Description { get; set; } public DateTime? SentDate { get; set; } public DataItem(string symbol, string series, float? askprice, float? bidprice, float? ltp, int? volume, string 

description, DateTime? sentdate) { Symbol = symbol; Series = series; AskPrice = askprice; BidPrice = bidprice; LTP = ltp; Volume = volume; Description = description; SentDate = sentdate; } }

  public partial class MainWindow : Window { private void btnSubscribe_Click(object sender, RoutedEventArgs e) { RCRProxy rp = new RCRProxy(); if (rp.Connect() == true) { // Console.WriteLine("please space to end session"); string tmp = "Start";// Console.ReadLine(); while (tmp != "Exit") { try { rp.SendMessage(tmp); } catch (Exception ex) { txtblkStatus.Text = ex.Message; } // tmp = Console.ReadLine(); // txtblkStatus.Text = rp.SendMessage(tmp); } } if (((ICommunicationObject)rp).State == CommunicationState.Opened) rp.Close(); } } } 

Answer 1

In the winforms/wpf application the communication between the server and the clients should be done on a secondary thread that is responsible of only that. If you put the action that you have on button btnSubscribe_Click in a new thread, the application will run ok.

See more details of how to work with threads in wpf:

c# wpf run button click on new thread

https://www.c-sharpcorner.com/UploadFile/1c8574/threads-in-wpf/

https://msdn.microsoft.com/en-us/library/ms741870(v=vs.85).aspx