Question

我使用以下代码在组中添加用户，并使用以下代码将用户保存在针对此特定组的数据库中。

服务器

  public class ChatHub : Hub
{


    public async Task JoinRoom(string user_Id, string room_Id, string user_Name)
    {
        AddLoginUser(room_Id, this.Context.ConnectionId, user_Id);
        await this.Groups.Add(this.Context.ConnectionId, room_Id);
    }


    public void Connect(string user_Id, string room_Id, string user_Name)
    {
        var id = Context.ConnectionId;

        Clients.Caller.onConnected(id, user_Name, GetRoomUser(room_Id), GetRoomMessage(room_Id));

        // send to all in group to update user list
        Clients.OthersInGroup(room_Id).onNewUserConnected(id, user_Name);
    }
  public override System.Threading.Tasks.Task OnDisconnected(bool stopCalled)
    {

        using (DataContext dc = new DataContext())
        {
            var item = dc.LoggedInUsers.FirstOrDefault(x => x.ConnectionId == Context.ConnectionId);
            if (item != null)
            {
                item.Connected = false;
                dc.SubmitChanges();

                Clients.OthersInGroup(item.RoomID.ToString()).onUserDisconnected(Context.ConnectionId, item.UserMaster.User_Name);
            }

            return base.OnDisconnected(stopCalled);
        }
    }
   }

 private void AddLoginUser(string room_Id, string connection_Id, string user_Id)
    {
        using (DataContext dc = new DataContext())
        {
            var checkUserLogedIn = (from user in dc.LoggedInUsers
                                    where (user.RoomID == Convert.ToInt32(room_Id) && user.UserID == Convert.ToInt32(user_Id))
                                    select user).SingleOrDefault();
            if (checkUserLogedIn == null)
            {
                LoggedInUser objLoggedInUser = new LoggedInUser();
                objLoggedInUser.ConnectionId = connection_Id;
                objLoggedInUser.UserID = Convert.ToInt32(user_Id);
                objLoggedInUser.RoomID = Convert.ToInt32(room_Id);
                objLoggedInUser.Connected = true;
                dc.LoggedInUsers.InsertOnSubmit(objLoggedInUser);
                dc.SubmitChanges();
            }
            else
            {
                if (!checkUserLogedIn.Connected)
                {
                    checkUserLogedIn.Connected = true;
                    dc.SubmitChanges();
                }
            }
        }
    }

问题：

假设我使用userid = 1登录roomid = 1和contextid = 123asd。如果我刷新我的窗口，那么contextid将会改变，现在如果我关闭浏览器选项卡然后关注查询：

var item = dc.LoggedInUsers.FirstOrDefault(x => x.ConnectionId == Context.ConnectionId);

没有找到针对最新connectionid的用户，因为当我在连接时保存用户时，connectionid是不同的。

如何在断开连接事件中为特定用户设置连接状态为false。

提前致谢。

Answer 1

OnConnected您应该保存所有connectionIds（与用户映射），connectionId应该是唯一的，而不是用户。因为用户可以同时与信号器建立多个连接（新标签）。

每次你应该在Onconnected上映射用户和connectionId。每次你应该删除那个connectionId，而不是OnDisconnected上用户的所有connectionIds。如果{i}不在列表中，则应该将connectionId添加到用户列表中（如果在OnReconnected上没有调用断开连接，即使用户未断开连接）也应该添加。

您应该根据此重构代码库。首先，您应该删除connectionId。然后，你可以检查;如果该用户没有留下任何记录（使用该connectionId映射），则可以发送消息。

检查here

我已经更改了一些代码，您可以根据这些知识改进此代码。您也应该在AddLoginUser上致电OnReconnected。

     public override System.Threading.Tasks.Task OnDisconnected(bool stopCalled)
                {
                    using (DataContext dc = new DataContext())
                    {
                        var item = dc.LoggedInUsers.FirstOrDefault(x => x.ConnectionId == Context.ConnectionId);
                        if (item != null)
                        {
                            dc.LoggedInUsers.Remove(item);
                            dc.SubmitChanges();
//If there is no other connection left with this user in this room send message.
                               if (!dc.LoggedInUsers.Any(x => x.RoomID==item.RoomID && x.userId==item.UserId)
                                   Clients.OthersInGrouproomId.ToString()).onUserDisconnected(Context.ConnectionId, item.UserMaster.User_Name);
                           }
                        return base.OnDisconnected(stopCalled);
                    }
                }
            }

            private void AddLoginUser(string room_Id, string connection_Id, string user_Id)
            {
                using (DataContext dc = new DataContext())
                {
//Just check connectionId uniqunes. You don't need connected field.
                    var checkUserLogedIn = (from user in dc.LoggedInUsers
                                            where user.ConnectionId == connection_Id
                                            select user).SingleOrDefault();
                    if (checkUserLogedIn == null)
                    {
                        LoggedInUser objLoggedInUser = new LoggedInUser();
                        objLoggedInUser.ConnectionId = connection_Id;
                        objLoggedInUser.UserID = Convert.ToInt32(user_Id);
                        objLoggedInUser.RoomID = Convert.ToInt32(room_Id);
                        dc.LoggedInUsers.InsertOnSubmit(objLoggedInUser);
                        dc.SubmitChanges();
                    }
                }
            }

SignalR（v2.2.0）OnDisconnected设置用户离线

1 个答案: