Verwenden von SignalR zum Implementieren der Push-Funktion in Asp.NET MVC

using System;
using Microsoft.AspNet.SignalR;
 
namespace SignalDemo
{
 public class ServerHub : Hub
 {
 private static readonly char[] Constant =
 {
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
 'w', 'x', 'y', 'z',
 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
 'W', 'X', 'Y', 'Z'
 };
 
 /// <summary>
 /// 供客户端调用的服务器端代码
 /// </summary>
 /// <param name="message"></param>
 public void Send(string message)
 {
 var name = GenerateRandomName(4);
 
 // 调用所有客户端的sendMessage方法
 Clients.All.sendMessage(name, message);
 }
 
 /// <summary>
 /// 产生随机用户名函数
 /// </summary>
 /// <param name="length">用户名长度</param>
 /// <returns></returns>
 public static string GenerateRandomName(int length)
 {
 var newRandom = new System.Text.StringBuilder(62);
 var rd = new Random();
 for (var i = 0; i < length; i++)
 {
 newRandom.Append(Constant[rd.Next(62)]);
 }
 return newRandom.ToString();
 }
 }
}

using Microsoft.Owin;
using Owin;
 
[assembly: OwinStartupAttribute(typeof(SignalDemo.Startup))]
namespace SignalDemo
{
 public partial class Startup
 {
 #region MyRegion
 public void Configuration(IAppBuilder app)
 {
 app.MapSignalR();
 ConfigureAuth(app);
 }
 #endregion
 }
}

using System.Web.Mvc;
 
namespace SignalDemo.Controllers
{
 public class HomeController : Controller
 {
 public ActionResult Chat()
 {
 return View();
 }
 }
}

@{
 ViewBag.Title = "Chat";
}
 
<h2>Chat</h2>
 
<div class="container">
 <input type="text" id="message" />
 <input type="button" id="sendmessage" value="Send" />
 <input type="hidden" id="displayname" />
 <ul id="discussion"></ul>
</div>
 
@section scripts
{
 <!--引用SignalR库. -->
 <script src="~/Scripts/jquery.signalR-2.2.1.min.js"></script>
 <!--引用自动生成的SignalR 集线器(Hub)脚本.在运行的时候在浏览器的Source下可看到 -->
 <script src="~/signalr/hubs"></script>
 <script>
 $(function () {
 // 引用自动生成的集线器代理
 var chat = $.connection.serverHub;
 // 定义服务器端调用的客户端sendMessage来显示新消息
 
 chat.client.sendMessage = function (name, message) {
 // 向页面添加消息
 $(&#39;#discussion&#39;).append(&#39;<li><strong>&#39; + htmlEncode(name)
 + &#39;</strong>: &#39; + htmlEncode(message) + &#39;</li>&#39;);
 };
 // 设置焦点到输入框
 $(&#39;#message&#39;).focus();
 // 开始连接服务器
 $.connection.hub.start().done(function () {
 $(&#39;#sendmessage&#39;).click(function () {
 // 调用服务器端集线器的Send方法
 chat.server.send($(&#39;#message&#39;).val());
 // 清空输入框信息并获取焦点
 $(&#39;#message&#39;).val(&#39;&#39;).focus();
 });
 });
 });
 
 // 为显示的消息进行Html编码
 function htmlEncode(value) {
 var encodedValue = $(&#39;<div />&#39;).text(value).html();
 return encodedValue;
 }
 </script>
}

using System.Web.Mvc;
using System.Web.Routing;
 
namespace SignalDemo
{
 public class RouteConfig
 {
 public static void RegisterRoutes(RouteCollection routes)
 {
 routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
 routes.MapRoute(
 name: "Default",
 url: "{controller}/{action}/{id}",
 defaults: new { controller = "Home", action = "Chat", id = UrlParameter.Optional }
 );
 }
 }
}

public class ServerHub : Hub
 {
 private static readonly char[] Constant =
 {
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
 'w', 'x', 'y', 'z',
 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
 'W', 'X', 'Y', 'Z'
 };
 
 /// <summary>
 /// 供客户端调用的服务器端代码
 /// </summary>
 /// <param name="message"></param>
 public void Send(string message)
 {
 var name = GenerateRandomName(4);
 
 // 调用所有客户端的sendMessage方法
 Clients.All.sendMessage(name, message);
 }
 
 /// <summary>
 /// 客户端连接的时候调用
 /// </summary>
 /// <returns></returns>
 public override Task OnConnected()
 {
 Trace.WriteLine("客户端连接成功");
 return base.OnConnected();
 }
 
 /// <summary>
 /// 产生随机用户名函数
 /// </summary>
 /// <param name="length">用户名长度</param>
 /// <returns></returns>
 public static string GenerateRandomName(int length)
 {
 var newRandom = new System.Text.StringBuilder(62);
 var rd = new Random();
 for (var i = 0; i < length; i++)
 {
 newRandom.Append(Constant[rd.Next(62)]);
 }
 return newRandom.ToString();
 }
 }

/// <summary>
 /// 启动SignalR服务，将SignalR服务寄宿在WPF程序中
 /// </summary>
 private void StartServer()
 {
 try
 {
 SignalR = WebApp.Start(ServerUri); // 启动SignalR服务
 }
 catch (TargetInvocationException)
 {
 WriteToConsole("一个服务已经运行在：" + ServerUri);
 // Dispatcher回调来设置UI控件状态
 this.Dispatcher.Invoke(() => ButtonStart.IsEnabled = true);
 return;
 }
 
 this.Dispatcher.Invoke(() => ButtonStop.IsEnabled = true);
 WriteToConsole("服务已经成功启动，地址为：" + ServerUri);
 }
 
public class ChatHub : Hub
 {
 public void Send(string name, string message)
 {
 Clients.All.addMessage(name, message);
 }
 
 public override Task OnConnected()
 {
 //
 Application.Current.Dispatcher.Invoke(() =>
 ((MainWindow)Application.Current.MainWindow).WriteToConsole("客户端连接，连接ID是: " + Context.ConnectionId));
 
 return base.OnConnected();
 }
 
 public override Task OnDisconnected(bool stopCalled)
 {
 Application.Current.Dispatcher.Invoke(() =>
 ((MainWindow)Application.Current.MainWindow).WriteToConsole("客户端断开连接，连接ID是: " + Context.ConnectionId));
 
 return base.OnDisconnected(true);
 }
 }
 
 public class Startup
 {
 public void Configuration(IAppBuilder app)
 {
 // 有关如何配置应用程序的详细信息，请访问 http://go.microsoft.com/fwlink/?LinkID=316888
 // 允许CORS跨域
 //app.UseCors(CorsOptions.AllowAll);
 app.MapSignalR();
 }
 }

public IHubProxy HubProxy { get; set; }
 const string ServerUri = "http://localhost:8888/signalr";
 public HubConnection Connection { get; set; }
 
 public MainWindow()
 {
 InitializeComponent();
 
 // 窗口启动时开始连接服务
 ConnectAsync();
 }
 
 /// <summary>
 /// 发送消息
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void ButtonSend_Click(object sender, RoutedEventArgs e)
 {
 // 通过代理来调用服务端的Send方法
 // 服务端Send方法再调用客户端的AddMessage方法将消息输出到消息框中
 HubProxy.Invoke("Send", GenerateRandomName(4), TextBoxMessage.Text.Trim());
 
 TextBoxMessage.Text = String.Empty;
 TextBoxMessage.Focus();
 }
 
 private async void ConnectAsync()
 {
 Connection = new HubConnection(ServerUri);
 Connection.Closed += Connection_Closed;
 
 // 创建一个集线器代理对象
 HubProxy = Connection.CreateHubProxy("ChatHub");
 
 // 供服务端调用，将消息输出到消息列表框中
 HubProxy.On<string, string>("AddMessage", (name, message) =>
 this.Dispatcher.Invoke(() =>
 RichTextBoxConsole.AppendText(String.Format("{0}: {1}\r", name, message))
 ));
 
 try
 {
 await Connection.Start();
 }
 catch (HttpRequestException)
 {
 // 连接失败
 return;
 }
 
 // 显示聊天控件
 ChatPanel.Visibility = Visibility.Visible;
 ButtonSend.IsEnabled = true;
 TextBoxMessage.Focus();
 RichTextBoxConsole.AppendText("连上服务：" + ServerUri + "\r");
 }