原文:

这里面有用到异步的相关知识，本人前几篇文章也简单的提到。

SignalR客户端要寄宿在.NET的客户端，必须安装Microsoft.AspNet.SignalR.Client。如何建立一个连接var hubConneciton=new HubConnection("http://www.contos.com/");IHubProxy stockTickerHubProxy=hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
        
         ("UpdateStockPrice",stock=>Console.WrireLine("Stock update");await hubConnection.Start(););Start是一个异步方法C#await connection.Start();cssconnection.Start().Wait();配置连接在建立连接之前可以做一些配置。设置最大并发数var hubConnection = new HubConnection("http://www.contoso.com/");IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
         
          ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));ServicePointManager.DefaultConnectionLimit = 10;await hubConnection.Start();默认最大并发数为2。添加连接字符串客户端var querystringData = new Dictionary
          
           ();querystringData.Add("contosochatversion", "1.0");var connection = new HubConnection("http://contoso.com/", querystringData);服务端public class StockTickerHub : Hub{    public override Task OnConnected()    {        var version = Context.QueryString["contosochatversion"];        if (version != "1.0")        {            Clients.Caller.notifyWrongVersion();        }        return base.OnConnected();    }}设置传输方法var hubConnection = new HubConnection("http://www.contoso.com/");IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
           
            ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));await hubConnection.Start(new LongPollingTransport());关于传输方式在Microsoft.AspNet.SignalR.Client.Transports命名空间下。LongPollingTransport、ServerSentEventsTransport、WebSocketTranspor、WebSocketTranspor。ForevenFrame不被包含在内，因为它只在浏览器中使用。指定HTTP头信息hubConnection = new hubConnection("http://www.contoso.com/");connection.Headers.Add("headername", "headervalue");IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
            
             ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));await connection.Start();指定客户端的证书使用connection对象的AddClientCertificate方法。hubConnection = new hubConnection("http://www.contoso.com/");hubConnection.AddClientCertificate(X509Certificate.CreateFromCertFile("MyCert.cer"));IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
             
              ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));await connection.Start();创建Hub代理服务端public class StockTickerHub : Hub[HubName("stockTicker")]public class StockTickerHub : Hub客户端var hubConnection = new HubConnection("http://www.contoso.com/");IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
              
               ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));await hubConnection.Start();var hubConnection = new HubConnection("http://www.contoso.com/");IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("stockTicker");stockTickerHubProxy.On
               
                ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));await hubConnection.Start();定义客户端方法使用代理的On方法去注册事件处理器，方法名符合驼峰命名法。服务端的Client.All.UpdateStockPrice方法名将会匹配客户端的udateStockPrice、updatestockprice、UpdateStockPrice方法。没有参数的方法服务端public class StockTickerHub : Hub{ public void NotifyAllClients() { Clients.All.Notify(); }}客户端var hubConnection = new HubConnection("http://www.contoso.com/");IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHub.On("notify", () => // Context is a reference to SynchronizationContext.Current Context.Post(delegate { textBox.Text += "Notified!\n"; }, null));await hubConnection.Start();有参数的方法使用On方法的泛型On
                
                 指定参数的类型。服务端public void BroadcastStockPrice(Stock stock){ context.Clients.Others.UpdateStockPrice(stock);}public class Stock{ public string Symbol { get; set; } public decimal Price { get; set; }}客户端stockTickerHubProxy.On
                 
                  ("UpdateStockPrice", stock => // Context is a reference to SynchronizationContext.Current Context.Post(delegate { textBox.Text += string.Format("Stock update for {0} new price {1}\n", stock.Symbol, stock.Price); }, null));也可以为动态对象stockTickerHubProxy.On("UpdateStockPrice", stock => // Context is a reference to SynchronizationContext.Current Context.Post(delegate { textBox.Text += string.Format("Stock update for {0} new price {1}\n", stock.Symbol, stock.Price); }, null));不通过On的泛型指定参数类型。移除方法C#var updateStockPriceHandler = stockTickerHubProxy.On
                  
                   ("UpdateStockPrice", stock => Context.Post(delegate { textBox.Text += string.Format("Stock update for {0} new price {1}\n", stock.Symbol, stock.Price); }, null));cssupdateStockPriceHandler.Dispose();客户端调用服务端的方法使用Hub代理的Invoke方法。没有返回值服务端public class StockTickerHub : Hub{ public void JoinGroup(string groupName) { Groups.Add(Context.ConnectionId, groupName); }}客户端stockTickerHubProxy.Invoke("JoinGroup", "SignalRChatRoom");有返回值服务端public IEnumerable
                   
                     AddStock(Stock stock){ _stockTicker.AddStock(stock); return _stockTicker.GetAllStocks();}public class Stock{ public string Symbol { get; set; } public decimal Price { get; set; }}客户端var stocks = stockTickerHub.Invoke
                    
                     
                      >("AddStock", new Stock() { Symbol = "MSFT" }).Result;foreach (Stock stock in stocks){ textBox.Text += string.Format("Symbol: {0} price: {1}\n", stock.Symbol, stock.Price);}连接生命周期事件SignalR提供以下可以处理的连接生命周期事件：Received：在连接上收到任何数据时触发。提供收到的数据。ConnectionSlow：当客户端检测到缓慢或频繁丢弃的连接时引发。Reconnecting：当底层传输开始重新连接时引发。Reconnected：当底层运输工具重新连接时提起。StateChanged：连接状态发生变化时触发。提供旧状态和新状态Closed：连接断开连接时触发。示例：hubConnection.ConnectionSlow += () => Console.WriteLine("Connection problems.");注册事件。处理错误如果没有在服务器上显式启用详细的错误消息，则SignalR在错误后返回的异常对象包含有关错误的最少信息。服务端开启详细信息var hubConfiguration = new HubConfiguration();hubConfiguration.EnableDetailedErrors = true;App.MapSignalR(hubConfiguration);为signalR引发的错误注册事件hubConnection.Error += ex => Console.WriteLine("SignalR error: {0}", ex.Message);在try-catch块中处理try{ IEnumerable
                      
                        stocks = await stockTickerHub.Invoke
                       
                        
                         >("GetAllStocks"); foreach (Stock stock in stocks) { Console.WriteLine("Symbol: {0} price: {1}", stock.Symbol, stock.Price); }}catch (Exception ex){ Console.WriteLine("Error invoking GetAllStocks: {0}", ex.Message);}启用客户端日记记录通过连接对象的TrackLevel和TraceWriter属性设置。var hubConnection = new HubConnection("http://www.contoso.com/");hubConnection.TraceLevel = TraceLevels.All;hubConnection.TraceWriter = Console.Out;IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("StockTickerHub");stockTickerHubProxy.On
                         
                          ("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));await hubConnection.Start();