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<Stock>("UpdateStockPrice",stock=>Console.WrireLine("Stock update");

await hubConnection.Start();

);

Start是一个异步方法

C#

await connection.Start();

css

connection.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<Stock>("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<string, string>();

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<Stock>("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<Stock>("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<Stock>("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<Stock>("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<Stock>("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<T>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<Stock>("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<Stock>("UpdateStockPrice", stock =>

    Context.Post(delegate

    {

        textBox.Text += string.Format("Stock update for {0} new price {1}\n", stock.Symbol, stock.Price);

    }, null)

);

css

updateStockPriceHandler.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<Stock> 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<IEnumerable<Stock>>("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<Stock> stocks = await stockTickerHub.Invoke<IEnumerable<Stock>>("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<Stock>("UpdateStockPrice", stock => Console.WriteLine("Stock update for {0} new price {1}", stock.Symbol, stock.Price));

await hubConnection.Start();