在客户端检测SignalR中的连接丢失

Question

我将一个简单的应用程序连接到托管我的Web应用程序的服务器。我的Web应用程序使用SignalR 2.一切都很顺利，我的小应用程序可以与Web应用程序同步并接收从它发送的消息。但是，当网页更新或服务器重新启动并失去连接时，应用程序无法理解连接从服务器丢失。以下是我的代码：

// initializing connection 
HubConnection connection; 
IHubProxy hub; 

connection = new HubConnection(serverAddress); 
hub = connection.CreateHubProxy("MyPanel"); 
hub.On<string>("ReciveText", (msg) => recieveFromServer(msg)); 

线程检查连接每隔1分钟，但每次检查时，连接的状态是“已连接”，而从服务器端的连接丢失。有什么我在这里失踪？

if (connection.State == ConnectionState.Disconnected) 
{ 
    // try to reconnect to server or do something 
} 

Answer 1

你可以尝试这样的事情：

从signalR官方自带的例子。

connection = new HubConnection(serverAddress);  
connection.Closed += Connection_Closed; 

/// <summary> 
/// If the server is stopped, the connection will time out after 30 seconds (default), and the 
/// Closed event will fire. 
/// </summary> 
void Connection_Closed() 
{ 
//do something 
} 

您可以使用StateChanged事件太像这样：

connection.StateChanged += Connection_StateChanged; 

private void Connection_StateChanged(StateChange obj) 
{ 
     MessageBox.Show(obj.NewState.ToString()); 
} 

编辑

你可以尝试每15秒重新与类似的东西：

private void Connection_StateChanged(StateChange obj) 
    { 

     if (obj.NewState == ConnectionState.Disconnected) 
     { 
      var current = DateTime.Now.TimeOfDay; 
      SetTimer(current.Add(TimeSpan.FromSeconds(30)), TimeSpan.FromSeconds(10), StartCon); 
     } 
     else 
     { 
      if (_timer != null) 
       _timer.Dispose(); 
     } 
    } 

    private async Task StartCon() 
    { 
     await Connection.Start(); 
    } 

    private Timer _timer; 
    private void SetTimer(TimeSpan starTime, TimeSpan every, Func<Task> action) 
    { 
     var current = DateTime.Now; 
     var timeToGo = starTime - current.TimeOfDay; 
     if (timeToGo < TimeSpan.Zero) 
     { 
      return; 
     } 
     _timer = new Timer(x => 
     { 
      action.Invoke(); 
     }, null, timeToGo, every); 
}