public async void AddConUserList(string user, string groupName)
{
var _user = new SignalRUser();
_user.UserName = user;
_user.ConnectID = Context.ConnectionId;
_user.OnlineTime = DateTime.Now;
_user.GroupName = groupName;
await Groups.AddToGroupAsync(Context.ConnectionId, groupName);
await Clients.Group(groupName).SendAsync("GetConList", conUserList.AddList(_user));
}
