public async Task AddToGroup(string roomNumber, string name) { await Groups.AddToGroupAsync(Context.ConnectionId, roomNumber); var tempUser = await _chatRoomService.UserList(roomNumber); if (tempUser.Contains(name)) { var r = new Random(); name = name + r.Next(10, 100).ToString(); await Clients.Client(Context.ConnectionId).SendAsync("NewName", name); } await _chatRoomService.AddUser(roomNumber, name); await Clients.Group(roomNumber).SendAsync("Send", $"{name} has joined the group."); var users = await _chatRoomService.UserList(roomNumber); await Clients.Group(roomNumber).SendAsync( "UserJoin", users); }