问题
When starting and stopping a SignalR client that is connected to a basic self hosted server like this:
async public void Start(string url)
{
_connection = new HubConnection(url);
_proxy = _connection.CreateHubProxy("hubname");
await _connection.Start().ContinueWith((task) => IsRunning = true);
}
public void Stop()
{
_connection.Stop();
}
I get the following exception when calling the "Stop" method (including trace messages):
SignalR.Transports.TransportHeartBeat Verbose: 0 : KeepAlive(c75fe282-a86d-406a-935b-5981b47bd472)
SignalR.Transports.TransportHeartBeat Information: 0 : Connection 1bdabc19-e0a7-4649-aabb-bade071ad6d0 is New.
SignalR.Transports.WebSocketTransport Information: 0 : Abort(1bdabc19-e0a7-4649-aabb-bade071ad6d0)
SignalR.Transports.TransportHeartBeat Information: 0 : Removing connection 1bdabc19-e0a7-4649-aabb-bade071ad6d0
SignalR.Transports.WebSocketTransport Information: 0 : End(1bdabc19-e0a7-4649-aabb-bade071ad6d0)
SignalR.Transports.WebSocketTransport Verbose: 0 : DrainWrites(1bdabc19-e0a7-4649-aabb-bade071ad6d0)
SignalR.Transports.WebSocketTransport Information: 0 : CloseSocket(1bdabc19-e0a7-4649-aabb-bade071ad6d0)
App.vshost.exe Error: 0 : Error while closing the websocket: System.Net.WebSockets.WebSocketException (0x80004005): An internal WebSocket error occurred. Please see the innerException, if present, for more details. ---> System.Net.Sockets.SocketException (0x80004005): An existing connection was forcibly closed by the remote host
at System.Net.WebSockets.WebSocketConnectionStream.WebSocketConnection.WriteAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken)
at System.Net.WebSockets.WebSocketConnectionStream.<WriteAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.WebSocketBase.<SendFrameAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.WebSocketBase.WebSocketOperation.<Process>d__47.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>d__17.MoveNext()
at System.Net.WebSockets.WebSocketBase.ThrowIfConvertibleException(String methodName, Exception exception, CancellationToken cancellationToken, Boolean aborted)
at System.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNet.SignalR.WebSockets.WebSocketHandler.<<CloseAsync>b__6>d__8.MoveNext()
App.vshost.exe Error: 0 : Error while closing the websocket: System.Net.WebSockets.WebSocketException (0x80004005): An internal WebSocket error occurred. Please see the innerException, if present, for more details. ---> System.Net.Sockets.SocketException (0x80004005): An existing connection was forcibly closed by the remote host
at System.Net.WebSockets.WebSocketConnectionStream.WebSocketConnection.WriteAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken)
at System.Net.WebSockets.WebSocketConnectionStream.<WriteAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.WebSocketBase.<SendFrameAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.WebSocketBase.WebSocketOperation.<Process>d__47.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>d__17.MoveNext()
at System.Net.WebSockets.WebSocketBase.ThrowIfConvertibleException(String methodName, Exception exception, CancellationToken cancellationToken, Boolean aborted)
at System.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNet.SignalR.WebSockets.WebSocketHandler.<<CloseAsync>b__6>d__8.MoveNext()
SignalR.Transports.WebSocketTransport Information: 0 : CompleteRequest (1bdabc19-e0a7-4649-aabb-bade071ad6d0)
SignalR.Transports.TransportHeartBeat Verbose: 0 : KeepAlive(c75fe282-a86d-406a-935b-5981b47bd472)
SignalR.Transports.TransportHeartBeat Verbose: 0 : KeepAlive(c75fe282-a86d-406a-935b-5981b47bd472)
The setups itself seem to work fine and devices can connect, send, receive, and disconnect. But with every disconnect I get the ugly above exception. Any idea what the problem could be? I am using SignalR 2.2.0 and Owin 1.2.2.
回答1:
Looks like a known issue which might be fixed in v3.
回答2:
Try providing a TimeSpan to the close method to give it time to actually close while waiting for any async processes which may be in progress:
public void Stop()
{
_connection.Stop(new TimeSpan(1000));
}
This worked for me.
回答3:
Ok guys, I know its lame. I am trying to shutdown signalr client when the mainwindow closes and I get a lot of exceptions that I can not catch and my process hangs. So i decided to kill the main process on form close.
private void OnClose(object sender, CancelEventArgs e){
try
{
var process = Process.GetCurrentProcess();
process.Kill();
//HubConnection.Stop();
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
}
回答4:
I solved this problem with
connection.Reconnecting += connection.Stop;
Because I found the connection state is always reconnecting
回答5:
If I understand correctly, you want to stop broadcasting message when client is disconnected. So my approach is use Connection Lifetime Events in SignalR. This is the official page : SignalRLifeTimeEvents
public override System.Threading.Tasks.Task OnDisconnected()
{
//-- When any client will close the browser or page this event will fire
return base.OnDisconnected();
}
来源：https://stackoverflow.com/questions/28708186/signalr-websocket-exception-when-closing-client