public class ChatHub : Hub    {        //声明静态变量存储当前在线用户        public static class UserHandler        {            public static Dictionary<string, string> ConnectedIds = new Dictionary<string, string>();        }        //用户进入页面时执行的（连接操作）        public void userConnected(string name)        {            //进行编码，防止XSS攻击            name = HttpUtility.HtmlEncode(name);            string message = "用户 " + name + " 登录";            //发送信息给其他人            Clients.Others.addList(Context.ConnectionId, name);            Clients.Others.hello(message);            //发送信息给自己，并显示上线清单            Clients.Caller.getList(UserHandler.ConnectedIds.Select(p => new { id = p.Key, name = p.Value }).ToList());            //新增目前使用者上线清单            UserHandler.ConnectedIds.Add(Context.ConnectionId, name);        }        //发送信息给所有人        public void sendAllMessage(string message)        {            message = HttpUtility.HtmlEncode(message);            var name = UserHandler.ConnectedIds.Where(p => p.Key == Context.ConnectionId).FirstOrDefault().Value;            message = name + "说：" + message;            Clients.All.sendAllMessge(message);        }        //发送信息给特定人        public void sendMessage(string ToId, string message)        {            message = HttpUtility.HtmlEncode(message);            var fromName = UserHandler.ConnectedIds.Where(p => p.Key == Context.ConnectionId).FirstOrDefault().Value;            message = fromName + " <span style=‘color:red‘>悄悄对你说</span>：" + message;            Clients.Client(ToId).sendMessage(message);        }        public override Task OnDisconnected()        {            //当使用者离开时，移除在清单内的ConnectionId            Clients.All.removeList(Context.ConnectionId);            UserHandler.ConnectedIds.Remove(Context.ConnectionId);            return base.OnDisconnected();        }}

<!--Reference the SignalR library. --><script src="../../Scripts/jquery.signalR-1.1.4.min.js" type="text/javascript"></script><!--Reference the autogenerated SignalR hub script. --><script src="../../signalr/hubs"></script><fieldset>    <legend>系统使用交流及问题在线提交</legend>    <div id="messageBox">        <ul id="messageList"></ul>    </div>    <div id="chatList">        <p>当前在线</p>        <ul id="list"></ul>    </div>    <div id="bar">        <div style="margin-top: 6px; float: left;">            <select id="box">                <option value="all">所有人</option>            </select>        </div>        <div style="margin: 5px; float: left;">            <input id="message" type="text" value="" />        </div>        <div style="margin: 5px; float: left;">            <input type="button" id="send" value="发 送" class="btn btn-success" />        </div>    </div>    <input type="hidden" id="UserName" value="@ViewBag.UserId" /></fieldset><script type="text/javascript">    var userID = "";    $(function () {        //回车查询        var $inp = $(‘input:text‘);        $inp.bind(‘keydown‘, function (e) {            var key = e.which;            if (key == 13) {                $(‘#send‘).click();            }        });        userID = $("#UserName").val();        //建立與Server端的Hub的物件，注意Hub的開頭字母一定要為小寫        var chat = $.connection.chatHub;        //取得所有上線清單        chat.client.getList = function (userList) {            var li = "";            $.each(userList, function (index, data) {                li += "<li id=‘" + data.id + "‘>" + data.name + "</li>";            });            $("#list").html(li);        }        //新增一筆上線人員        chat.client.addList = function (id, name) {            var li = "<li id=‘" + id + "‘>" + name + "</li>";            $("#list").append(li);        }        //移除一筆上線人員        chat.client.removeList = function (id) {            $("#" + id).remove();        }        //全體聊天        chat.client.sendAllMessge = function (message) {            $("#messageList").append("<li>sendAllMessge" + message + "</li>");        }        //密語聊天        chat.client.sendMessage = function (message) {            $("#messageList").append("<li>sendMessage" + message + "</li>");        }        chat.client.hello = function (message) {            $("#messageList").append("<li>hello" + message + "</li");        }        //將連線打開        $.connection.hub.start().done(function () {            //當連線完成後，呼叫Server端的userConnected方法，並傳送使用者姓名給Server            chat.server.userConnected(userID);        });;        $("#send").click(function () {            var to = $("#box").val();            //當to為all代表全體聊天，否則為私密聊天            if (to == "all") {                chat.server.sendAllMessage($("#message").val());            } else {                chat.server.sendMessage(to, $("#message").val());            }            $("#message").val(‘‘);        });        $("#list li").live("click", function () {            var $this = $(this);            var id = $this.attr("id");            var text = $this.text();            //防止重複加入密語清單            if ($("#box").has("." + id).length > 0)                return false;            var option = "<option></option>"            $("#box").append(option).find("option:last").val(id).text(text).attr({ "selected": "selected" }).addClass(id);        });    });</script>