public class Startup
 {
 public void Configuration(IAppBuilder app)
 {
  app.MapSignalR();
 }
 }

<script src="~/Scripts/jquery-1.10.2.js"></script>
<script src="~/Scripts/jquery.signalR-2.2.1.min.js"></script> 
<script src="~/signalr/hubs"></script>

[HubName("simpleHub")]
 public class SimpleHub : Hub
 { 
 public void SendMsg(string msg)
 {
  
 }

 }

<script type="text/javascript"> 
 var ticker = $.connection.simpleHub;
 $.connection.hub.start();

 $("#btn").click(function () {

 // 鏈接完成以后，可以發(fā)送消息至服務(wù)端
 ticker.server.sendMsg("需要發(fā)送的消息");
 });
 
</script>

[HubName("simpleHub")]
 public class SimpleHub : Hub
 {
 public void SendMsg(string msg)
 {
  // 獲取鏈接id
  var connectionId = Context.ConnectionId; 
  // 獲取cookie
  var cookie = Context.RequestCookies;

 }

 }

[HubName("simpleHub")]
 public class SimpleHub : Hub
 {
 public void SendMsg(string msg)
 {
  Clients.All.msg("發(fā)送給客戶端的消息"); 
 }

 }

<script type="text/javascript">

 var ticker = $.connection.groupChatHub;
 $.connection.hub.start();

 ticker.client.msg = function (data) {
 console.log(data);
 } 
</script>

// 所有人
Clients.All.msg("發(fā)送給客戶端的消息"); 
// 特定 cooectionId
Clients.Client("connectionId").msg("發(fā)送給客戶端的消息");
// 特定 group
Clients.Group("groupName").msg("發(fā)送給客戶端的消息");

/// <summary>
 /// SignalR Hub 群聊類
 /// </summary>
 [HubName("groupChatHub")] // 標(biāo)記名稱供js調(diào)用
 public class GroupChatHub : Hub
 {
 /// <summary>
 /// 用戶名
 /// </summary>
 private string UserName
 {
  get
  {
  var userName = Context.RequestCookies["USERNAME"];
  return userName == null ? "" : HttpUtility.UrlDecode(userName.Value);
  }
 }

 /// <summary>
 /// 在線用戶
 /// </summary>
 private static Dictionary<string, int> _onlineUser = new Dictionary<string, int>();

 /// <summary>
 /// 開(kāi)始連接
 /// </summary>
 /// <returns></returns>
 public override Task OnConnected()
 {
  Connected();
  return base.OnConnected();
 }


 /// <summary>
 /// 重新鏈接
 /// </summary>
 /// <returns></returns>
 public override Task OnReconnected()
 {
  Connected();
  return base.OnReconnected();
 }


 private void Connected()
 {
  // 處理在線人員
  if (!_onlineUser.ContainsKey(UserName)) // 如果名稱不存在，則是新用戶
  {

  // 加入在線人員
  _onlineUser.Add(UserName, 1);

  // 向客戶端發(fā)送在線人員
  Clients.All.publshUser(_onlineUser.Select(i => i.Key));

  // 向客戶端發(fā)送加入聊天消息
  Clients.All.publshMsg(FormatMsg("系統(tǒng)消息", UserName + "加入聊天"));
  }
  else
  {
  // 如果是已經(jīng)存在的用戶，則把在線鏈接的個(gè)數(shù)+1
  _onlineUser[UserName] = _onlineUser[UserName] + 1;
  }

  // 加入Hub Group，為了發(fā)送單獨(dú)消息
  Groups.Add(Context.ConnectionId, "GROUP-" + UserName);
 }


 /// <summary>
 /// 結(jié)束連接
 /// </summary>
 /// <param name="stopCalled"></param>
 /// <returns></returns>
 public override Task OnDisconnected(bool stopCalled)
 {
  // 人員鏈接數(shù)-1
  _onlineUser[UserName] = _onlineUser[UserName] - 1;

  // 判斷是否斷開(kāi)了所有的鏈接
  if (_onlineUser[UserName] == 0)
  {
  // 移除在線人員
  _onlineUser.Remove(UserName);

  // 向客戶端發(fā)送在線人員
  Clients.All.publshUser(_onlineUser.Select(i => i.Key));

  // 向客戶端發(fā)送退出聊天消息
  Clients.All.publshMsg(FormatMsg("系統(tǒng)消息", UserName + "退出聊天"));
  }

  // 移除Hub Group
  Groups.Remove(Context.ConnectionId, "GROUP-" + UserName);
  return base.OnDisconnected(stopCalled);
 }

 /// <summary>
 /// 發(fā)送消息，供客戶端調(diào)用
 /// </summary>
 /// <param name="user">用戶名，如果為0，則是發(fā)送給所有人</param>
 /// <param name="msg">消息</param>
 public void SendMsg(string user, string msg)
 {
  if (user == "0")
  {
  // 發(fā)送給所有用戶消息
  Clients.All.publshMsg(FormatMsg(UserName, msg));
  }
  else
  {
  //// 發(fā)送給自己消息
  //Clients.Group("GROUP-" + UserName).publshMsg(FormatMsg(UserName, msg));

  //// 發(fā)送給選擇的人員
  //Clients.Group("GROUP-" + user).publshMsg(FormatMsg(UserName, msg));


  // 發(fā)送給自己消息
  Clients.Groups(new List<string> { "GROUP-" + UserName, "GROUP-" + user }).publshMsg(FormatMsg(UserName, msg));

  }
 }


 /// <summary>
 /// 格式化發(fā)送的消息
 /// </summary>
 /// <param name="name"></param>
 /// <param name="msg"></param>
 /// <returns></returns>
 private dynamic FormatMsg(string name, string msg)
 {
  return new { Name = name, Msg = HttpUtility.HtmlEncode(msg), Time = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") };
 }
 }

<script type="text/javascript">
 $(function () {

  // 鏈接hub
  var ticker = $.connection.groupChatHub;
  $.connection.hub.start();

  // 接收服務(wù)端發(fā)送的消息
  $.extend(ticker.client, {

  // 接收聊天消息
  publshMsg: function (data) {
   $("#msg").append("<li><span class='p'>" + data.Name + "：</span>" + data.Msg + " <span class='time'>" + data.Time + "</span></li>")
   $("#msg").parents("div")[0].scrollTop = $("#msg").parents("div")[0].scrollHeight;
  },

  // 接收在線人員，然后加入Select，以供單獨(dú)聊天選中
  publshUser: function (data) {
   $("#count").text(data.length);
   $("#users").empty();
   $("#users").append('<option value="0">所有人</option>');
   for (var i = 0; i < data.length; i++) {
   $("#users").append('<option value="' + data[i] + '">' + data[i] + '</option>')
   }

  }
  });

  // 發(fā)送消息按鈕
  $("#btn-send").click(function () {
  var msg = $("#txt-msg").val();
  if (!msg) {
   alert('請(qǐng)輸入內(nèi)容！'); return false;
  }
  $("#txt-msg").val('');

  // 主動(dòng)發(fā)送消息，傳入發(fā)送給誰(shuí)，和發(fā)送的內(nèi)容。
  ticker.server.sendMsg($("#users").val(), msg);
  });

 });
 </script>

<h2>
 群聊系統(tǒng)（<span id="count">1</span>人在線）：@ViewBag.UserName
</h2>


<div style="overflow:auto;height:300px">
 <ul id="msg"></ul>
</div>

<select id="users" class="form-control" style="max-width:150px;">
 <option value="0">所有人</option>
</select>

<input type="text" onkeydown='if (event.keyCode == 13) { $("#btn-send").click() }' class="form-control" id="txt-msg" placeholder="內(nèi)容" style="max-width:400px;" />
<br />
<button type="button" id="btn-send">發(fā)送</button>

/// <summary>
 /// 主動(dòng)發(fā)送給用戶消息，單例模式
 /// </summary>
 public class GroupChat
 {
 /// <summary>
 /// Clients，用來(lái)主動(dòng)發(fā)送消息
 /// </summary>
 private IHubConnectionContext<dynamic> Clients { get; set; }

 private readonly static GroupChat _instance = new GroupChat(GlobalHost.ConnectionManager.GetHubContext<GroupChatHub>().Clients);

 private GroupChat(IHubConnectionContext<dynamic> clients)
 {
  Clients = clients;
 }

 public static GroupChat Instance
 {
  get
  {
  return _instance;
  }
 }


 /// <summary>
 /// 主動(dòng)給所有人發(fā)送消息，系統(tǒng)直接調(diào)用
 /// </summary>
 /// <param name="msg"></param>
 public void SendSystemMsg(string msg)
 {
  Clients.All.publshMsg(new { Name = "系統(tǒng)消息", Msg = msg, Time = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") });
 }
 }