SignalR HubConnection StopAsync 抛出 ObjectDisposedException

如何解决SignalR HubConnection StopAsync 抛出 ObjectDisposedException

我们有一个 WPF 客户端，它通过 SignalR 连接到我们的一台服务器。关闭 WPF 客户端时，我们也会关闭 SignalR HubConnection：

    public HubConnection Connection => _connection ??= GetConnection();

    private HubConnection GetConnection()
    {
        var host = ConfigurationManager.AppSettings["SignalRHost"];
        var connection = new HubConnectionBuilder()
            .WithUrl(host)
            .Build();
        connection.Closed += ConnectionOnClosed;
        return connection;
    }

    private async Task ConnectionOnClosed(Exception exception)
    {
        // The connection is disconnected
        if (_disconnecting)
        {
            // The disconnect was requested by the client
            Connection.Closed -= ConnectionOnClosed;
            Logger.information("The connection to SignalR hub was closed.");
        }
        else
        {
            await StartAsync();
        }

    }

    public async Task disconnect()
    {
        if (_disconnecting) return;
        try
        {
            _disconnecting = true;
            await _connection.StopAsync();
        }
        catch (Exception e)
        {
            Logger.Error(e,"Error in closing connection");
        }
        finally
        {
            await _connection.disposeAsync();
            _connection = null;
        }
    }

调用 CloseAsync 会导致两个 ObjectdisposedException。我只有部分堆栈跟踪（这似乎是我的 VS 中的另一个问题）：

    System.dll!System.Net.sockets.NetworkStream.InternalSocket.get() Line 136   
System.dll!System.Net.PooledStream.CancelPendingIoAndCloseIfSafe(bool closeWithTimeout,int timeout) Line 596   
System.dll!System.Net.PooledStream.Close(int timeout) Line 682  
System.dll!System.Net.Connection.AbortOrdisassociate(System.Net.HttpWebRequest request,System.Net.WebException webException) Line 2859 
System.dll!System.Net.HttpWebRequest.Abort(System.Exception exception,int abortState) Line 3173    
System.dll!System.Net.HttpWebRequest.Abort() Line 3133  
System.dll!System.Net.WebSockets.ClientWebSocket.AbortRequest(object obj) Line 366  
mscorlib.dll!System.Threading.CancellationCallbackInfo.ExecutionContextCallback(object obj) Line 1031   
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext,System.Threading.ContextCallback callback,object state,bool preserveSyncCtx) Line 980  
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext,bool preserveSyncCtx) Line 928  
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext,object state) Line 917    
mscorlib.dll!System.Threading.CancellationCallbackInfo.ExecuteCallback() Line 1021  
mscorlib.dll!System.Threading.CancellationTokenSource.CancellationCallbackCoreWork(System.Threading.CancellationCallbackCoreWorkArguments args) Line 863    
mscorlib.dll!System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(bool throwOnFirstException) Line 808  
mscorlib.dll!System.Threading.CancellationTokenSource.NotifyCancellation(bool throwOnFirstException) Line 743   
System.dll!System.Net.WebSockets.ClientWebSocket.dispose() Line 377 
System.dll!System.Net.WebSockets.ClientWebSocket.Abort() Line 360   
Microsoft.AspNetCore.Http.Connections.Client.dll!Microsoft.AspNetCore.Http.Connections.Client.Internal.WebSocketsTransport.ProcessSocketAsync(System.Net.WebSockets.WebSocket socket) Line 220  

接下来：

>   System.dll!System.Net.sockets.NetworkStream.InternalSocket.get() Line 136   C#
System.dll!System.Net.PooledStream.CancelPendingIoAndCloseIfSafe(bool closeWithTimeout,int timeout) Line 596   C#
System.dll!System.Net.PooledStream.Close(int timeout) Line 682  C#
System.dll!System.Net.Connection.AbortSocket(bool isAbortState) Line 2901   C#
System.dll!System.Net.ConnectStream.CloseInternal(bool internalCall,bool aborting) Line 2707   C#
System.dll!System.Net.ConnectStream.System.Net.ICloseEx.CloseEx(System.Net.CloseExState closeState) Line 2426   C#
System.dll!System.Net.HttpWebResponse.Abort() Line 479  C#
System.dll!System.Net.HttpWebRequest.SetResponse(System.Exception E) Line 3968  C#
System.dll!System.Net.HttpWebRequest.SetAndOrProcessResponse(object responSEOrException) Line 3661  C#
System.dll!System.Net.ConnectionReturnResult.SetResponses(System.Net.ConnectionReturnResult returnResult) Line 205  C#
System.dll!System.Net.Connection.AbortOrdisassociate(System.Net.HttpWebRequest request,System.Net.WebException webException) Line 2873 C#
System.dll!System.Net.HttpWebRequest.Abort(System.Exception exception,int abortState) Line 3173    C#
System.dll!System.Net.HttpWebRequest.Abort() Line 3133  C#
System.Net.Http.dll!System.Net.Http.httpclienthandler.OnCancel(object state) Line 1210  C#
mscorlib.dll!System.Threading.CancellationCallbackInfo.ExecutionContextCallback(object obj) Line 1031   C#
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext,bool preserveSyncCtx) Line 980  C#
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext,bool preserveSyncCtx) Line 928  C#
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext,object state) Line 917    C#
mscorlib.dll!System.Threading.CancellationCallbackInfo.ExecuteCallback() Line 1021  C#
mscorlib.dll!System.Threading.CancellationTokenSource.CancellationCallbackCoreWork(System.Threading.CancellationCallbackCoreWorkArguments args) Line 863    C#
mscorlib.dll!System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(bool throwOnFirstException) Line 808  C#
mscorlib.dll!System.Threading.CancellationTokenSource.NotifyCancellation(bool throwOnFirstException) Line 743   C#
mscorlib.dll!System.Threading.CancellationTokenSource.LinkedTokenCancelDelegate(object source) Line 91  C#
mscorlib.dll!System.Threading.CancellationCallbackInfo.ExecutionContextCallback(object obj) Line 1031   C#
mscorlib.dll!System.Threading.CancellationCallbackInfo.ExecuteCallback() Line 1021  C#
mscorlib.dll!System.Threading.CancellationTokenSource.CancellationCallbackCoreWork(System.Threading.CancellationCallbackCoreWorkArguments args) Line 863    C#
mscorlib.dll!System.Threading.CancellationTokenSource.ExecuteCallbackHandlers(bool throwOnFirstException) Line 808  C#
mscorlib.dll!System.Threading.CancellationTokenSource.NotifyCancellation(bool throwOnFirstException) Line 743   C#
mscorlib.dll!System.Threading.CancellationTokenSource.TimerCallbackLogic(object obj) Line 534   C#
mscorlib.dll!System.Threading.TimerQueueTimer.CallCallbackInContext(object state) Line 730  C#
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext,bool preserveSyncCtx) Line 928  C#
mscorlib.dll!System.Threading.TimerQueueTimer.CallCallback() Line 713   C#
mscorlib.dll!System.Threading.TimerQueueTimer.Fire() Line 670   C#
mscorlib.dll!System.Threading.TimerQueue.FireQueuedTimerCompletion(object state) Line 444   C#
mscorlib.dll!System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem() Line 1252    C#
mscorlib.dll!System.Threading.ThreadPoolWorkQueue.dispatch() Line 820   C#
mscorlib.dll!System.Threading._ThreadPoolWaitCallback.PerformWaitCallback() Line 1161   C#

服务器在 Visual Studio 中运行，地址为 http://localhost:5008/tubahub。在同一台机器上的 IIS 中运行服务器时，由于超时，我们在调用 StopAsync 时也会收到 SocketException。也许这是相关的。