Asp.net使用SignalR实现聊天室的功能

// IGroupManager接口提供如下方法
// 作用:将连接ID加入某个组
// Context.ConnectionId 连接ID,每个页面连接集线器即会产生唯一ID
// roomName分组的名称
Groups.Add(Context.ConnectionId, roomName);

// 作用:将连接ID从某个分组移除
Groups.Remove(Context.ConnectionId, roomName);

// IHubConnectionContext接口提供了如下方法
// 调用客户端方法向房间内所有用户群发消息 
// Room:分组名称
// new string[0]:过滤(不发送)的连接ID数组
 Clients.Group(Room, new string[0]).clientMethod

/// <summary>
 /// 用户类
 /// </summary>
 public class User
 {
  /// <summary>
  /// 用户Id
  /// </summary>
  public string UserId { get; set; }

  /// <summary>
  /// 用户的连接集合
  /// </summary>
  public List<Connection> Connections { get; set; }

  /// <summary>
  /// 用户房间集合，一个用户可以加入多个房间
  /// </summary>
  public List<ChatRoom> Rooms { get; set; }

  public User()
  {
   Connections = new List<Connection>();
   Rooms = new List<ChatRoom>();
  }
 }

 public class Connection
 {
  //连接ID
  public string ConnectionId { get; set; }

  //用户代理
  public string UserAgent { get; set; }
  //是否连接
  public bool Connected { get; set; } 
 }

  /// <summary>
 /// 房间类
 /// </summary>
 public class ChatRoom
 {
  // 房间名称
  public string RoomName { get; set; }

  // 用户集合
  public List<User> Users { get; set; }

  public ChatRoom()
  {
   Users = new List<User>();
  }
 }

 /// <summary>
 /// 上下文类，用来模拟EF中的DbContext
 /// </summary>
 public class ChatContext
 {
  public List<User> Users { get; set; }

  public List<Connection> Connections { get; set; }

  public List<ChatRoom> Rooms { get; set; }

  public ChatContext()
  {
   Users = new List<User>();
   Connections = new List<Connection>();
   Rooms = new List<ChatRoom>();
  }
 }

[HubName("chatRoomHub")]
 public class GroupsHub : Hub
 {
  public static ChatContext DbContext = new ChatContext();

  #region IHub Members
  // 重写Hub连接事件
  public override Task OnConnected()
  {
   // 查询用户
   var user = DbContext.Users.FirstOrDefault(u => u.UserId == Context.ConnectionId);

   if (user == null)
   {
    user = new User
    {
     UserId = Context.ConnectionId
    };

    DbContext.Users.Add(user);
   }

   // 发送房间列表
   var items = DbContext.Rooms.Select(p => new {p.RoomName});
   Clients.Client(this.Context.ConnectionId).getRoomList(JsonHelper.ToJsonString(items.ToList()));
   return base.OnConnected();
  }

  // 重写Hub连接断开的事件
  public override Task OnDisconnected(bool stopCalled)
  {
   // 查询用户
   var user = DbContext.Users.FirstOrDefault(u => u.UserId == Context.ConnectionId);

   if (user != null)
   {
    // 删除用户
    DbContext.Users.Remove(user);

    // 从房间中移除用户
    foreach (var item in user.Rooms)
    {
     RemoveUserFromRoom(item.RoomName);
    }
   }
   return base.OnDisconnected(stopCalled);
  }

  #endregion 

  #region Public Methods

  // 为所有用户更新房间列表
  public void UpdateRoomList()
  {
   var itme = DbContext.Rooms.Select(p => new {p.RoomName});
   var jsondata = JsonHelper.ToJsonString(itme.ToList());
   Clients.All.getRoomlist(jsondata);
  }

  /// <summary>
  /// 加入聊天室
  /// </summary>
  public void JoinRoom(string roomName)
  {
   // 查询聊天室
   var room = DbContext.Rooms.Find(p => p.RoomName == roomName);

   // 存在则加入
   if (room == null) return;

   // 查找房间中是否存在此用户
   var isExistUser = room.Users.FirstOrDefault(u => u.UserId == Context.ConnectionId);

   // 不存在则加入
   if (isExistUser == null)
   {
    var user = DbContext.Users.Find(u => u.UserId == Context.ConnectionId);
    user.Rooms.Add(room);
    room.Users.Add(user);
    
    // 将客户端的连接ID加入到组里面
    Groups.Add(Context.ConnectionId, roomName);

    //调用此连接用户的本地JS(显示房间)
    Clients.Client(Context.ConnectionId).joinRoom(roomName);
   }
   else
   {
    Clients.Client(Context.ConnectionId).showMessage("请勿重复加入房间!");
   }
  }

  /// <summary>
  /// 创建聊天室
  /// </summary>
  /// <param name="roomName"></param>
  public void CreateRoom(string roomName)
  {
   var room = DbContext.Rooms.Find(a => a.RoomName == roomName);
   if (room == null)
   {
    var cr = new ChatRoom
    {
     RoomName = roomName
    };

    //将房间加入列表
    DbContext.Rooms.Add(cr);

    // 本人加入聊天室
    JoinRoom(roomName);
    UpdateRoomList();
   }
   else
   {
    Clients.Client(Context.ConnectionId).showMessage("房间名重复!");
   }
  }

  public void RemoveUserFromRoom(string roomName)
  {
   //查找房间是否存在
   var room = DbContext.Rooms.Find(a => a.RoomName == roomName);

   //存在则进入删除
   if (room == null)
   {
    Clients.Client(Context.ConnectionId).showMessage("房间名不存在!");
    return;
   }

   // 查找要删除的用户
   var user = room.Users.FirstOrDefault(a => a.UserId == Context.ConnectionId);
   // 移除此用户
   room.Users.Remove(user);
   //如果房间人数为0,则删除房间
   if (room.Users.Count <= 0)
   {
    DbContext.Rooms.Remove(room);
   }

   Groups.Remove(Context.ConnectionId, roomName);

   //提示客户端
   Clients.Client(Context.ConnectionId).removeRoom("退出成功!");
  }

  /// <summary>
  /// 给房间内所有的用户发送消息
  /// </summary>
  /// <param name="room">房间名</param>
  /// <param name="message">信息</param>
  public void SendMessage(string room, string message)
  {
   // 调用房间内所有客户端的sendMessage方法
   // 因为在加入房间的时候，已经将客户端的ConnectionId添加到Groups对象中了，所有可以根据房间名找到房间内的所有连接Id
   // 其实我们也可以自己实现Group方法，我们只需要用List记录所有加入房间的ConnectionId
   // 然后调用Clients.Clients(connectionIdList),参数为我们记录的连接Id数组。
   Clients.Group(room, new string[0]).sendMessage(room, message + " " + DateTime.Now);
  }
  #endregion 
}

@{
 Layout = null;
}

<!DOCTYPE html>

<html>
<head>
 <meta name="viewport" content="width=device-width" />
 <title>Index</title>
 <script src="~/Scripts/jquery-2.2.2.min.js"></script>
 <script src="~/Scripts/jquery.signalR-2.2.0.min.js"></script>
 <script src="~/Scripts/layer/layer.min.js"></script>
 <!--这里要注意,这是虚拟目录,也就是你在OWIN Startup中注册的地址-->
 <script src="/signalr/hubs"></script>

 <script type="text/javascript">
  var chat;
  var roomcount = 0;
  
  $(function() {
   chat = $.connection.chatRoomHub;
   chat.client.showMessage = function(message) {
    alert(message);
   };
   chat.client.sendMessage = function(roomname, message) {
    $("#" + roomname).find("ul").each(function() {
     $(this).append('<li>' + message + '</li>');
    });
   };
   chat.client.removeRoom = function(data) {
    alert(data);
   };
   chat.client.joinRoom = function (roomname) {
    var html = '<div style="float:left; margin-left:360px; border:double; height:528px;width:493px" id="' + roomname + '" roomname="' + roomname + '"><button onclick="RemoveRoom(this)">退出</button>\
         ' + roomname + '房间\
            聊天记录如下:<ul>\
            </ul>\
         <textarea class="ChatCore_write" id="ChatCore_write" style="width:400px"></textarea> <button onclick="SendMessage(this)">发送</button>\
         </div>';
    $("#RoomList").append(html);
   };

   //注册查询房间列表的方法
   chat.client.getRoomlist = function(data) {
    if (data) {
     var jsondata = $.parseJSON(data);
     $("#roomlist").html(" ");
     for (var i = 0; i < jsondata.length; i++) {
      var html = ' <li>房间名:' + jsondata[i].RoomName + '<button roomname="' + jsondata[i].RoomName + '" onclick="AddRoom(this)">加入</button></li>';
      $("#roomlist").append(html);
     }
    }
   };
   // 获取用户名称。
   $('#username').html(prompt('请输入您的名称:', ''));

   $.connection.hub.start().done(function() {
    $('#CreatRoom').click(function() {
     chat.server.createRoom($("#Roomname").val());
    });
   });
  });
  
  function SendMessage(btn) {
   var message = $(btn).prev().val();
   var room = $(btn).parent();
   var username = $("#username").html();
   message = username + ":" + message;
   var roomname = $(room).attr("roomname");
   chat.server.sendMessage(roomname, message);
   $(btn).prev().val('').focus();
  }
  
  function RemoveRoom(btn) {
   var room = $(btn).parent();
   var roomname = $(room).attr("roomname");
   chat.server.removeUserFromRoom(roomname);
  }
  
  function AddRoom(roomname) {
   var data =$(roomname).attr("roomname");
   chat.server.joinRoom(data);
  }

 </script>
</head>
<body>
 <div>
  <div>名称:<p id="username"></p></div>
  输入房间名:
  <input type="text" value="聊天室1" id="Roomname" />
  <button id="CreatRoom">创建聊天室</button>
 </div>
 <div style="float:left;border:double">
  <div>房间列表</div>
  <ul id="roomlist"></ul>
 </div>
 <div id="RoomList">
 </div>
</body>
</html>

/// <summary>
 /// JSON 帮助类
 /// </summary>
 public class JsonHelper
 {
  /// <summary>
  /// 从一个对象信息生成Json字符串
  /// </summary>
  /// <param name="obj"></param>
  /// <returns></returns>
  public static string ToJsonString(object obj)
  {
   return JsonConvert.SerializeObject(obj);
  }

  /// <summary>
  /// 从Json字符串生成对象
  /// </summary>
  /// <typeparam name="T"></typeparam>
  /// <param name="jsonString"></param>
  /// <returns></returns>
  public static T ToObject<T>(string jsonString)
  {
   return JsonConvert.DeserializeObject<T>(jsonString);
  }
 }