public User GetInformationUser(string username)
        {
            ChatDBDataContext dataContext = new ChatDBDataContext();
            var existusers = (from u in dataContext.users
                              where u.username == username
                              select u).Single();
            User newuser = new User();

            newuser.userid   = existusers.userid;
            newuser.username = existusers.username;
            newuser.password = existusers.password;
            newuser.avarta   = existusers.avarta;
            return(newuser);
        }
        public void Login(string username, string password)
        {
            ChatDBDataContext chatdb = new ChatDBDataContext();
            int exist = 0;

            lock (SyncObj)
            {
                var existusers = from u in chatdb.users
                                 where u.username == username
                                 select u;
                if (existusers.FirstOrDefault() != null)
                {
                    exist = 1;
                }

                var Users = from U in DB.users
                            where U.username == username && U.password == password
                            select U;
                if (Users.Count() == 0)
                {
                    if (exist == 1)
                    {
                        //TrackedFault trackedFault = new TrackedFault(Guid.NewGuid(), Username, "Password is incorrect!", DateTime.Now);
                        //throw new FaultException<TrackedFault>(trackedFault, "Password isn't correct", FaultCode.CreateReceiverFaultCode(new FaultCode("Login")));
                        //return 2;
                        throw new Exception("Mật Khẩu sai!");
                    }
                    else
                    {
                        throw new Exception("Tên đăng nhập hoặc mật khẩu không đúng! Thử lại!");
                    }
                }
                else
                {
                    //Username da dang nhap nen co trong danh sach callback
                    if (ClientCallBacks.ContainsKey(username))
                    {
                        throw new Exception(username + "đang online!");
                    }
                    else
                    {
                        CheckOnlineListFriends(username);
                        ClientCallBacks.Add(username, CurrentCallback);
                    }
                }
            }
        }
 public User GetInformationUser(string username)
 {
     ChatDBDataContext dataContext = new ChatDBDataContext();
     var existusers = (from u in dataContext.users
                       where u.username == username
                       select u).Single();
     User newuser = new User();
     newuser.userid = existusers.userid;
     newuser.username = existusers.username;
     newuser.password = existusers.password;
     newuser.avarta = existusers.avarta;
     return newuser;
 }
        public void Login(string username, string password)
        {
            ChatDBDataContext chatdb = new ChatDBDataContext();
            int exist = 0;
            lock (SyncObj)
            {
                var existusers = from u in chatdb.users
                                 where u.username == username
                                 select u;
                if (existusers.FirstOrDefault()!=null)
                {
                    exist = 1;
                }

                var Users = from U in DB.users
                             where U.username == username && U.password == password
                             select U;
                if (Users.Count() == 0)
                {

                    if (exist == 1)
                    {
                        //TrackedFault trackedFault = new TrackedFault(Guid.NewGuid(), Username, "Password is incorrect!", DateTime.Now);
                        //throw new FaultException<TrackedFault>(trackedFault, "Password isn't correct", FaultCode.CreateReceiverFaultCode(new FaultCode("Login")));
                        //return 2;
                        throw new Exception("Mật Khẩu sai!");
                    }
                    else
                    {
                        throw new Exception("Tên đăng nhập hoặc mật khẩu không đúng! Thử lại!");
                    }
                }
                else
                {
                    //Username da dang nhap nen co trong danh sach callback
                    if (ClientCallBacks.ContainsKey(username))
                        throw new Exception(username + "đang online!");
                    else
                    {
                        CheckOnlineListFriends(username);
                        ClientCallBacks.Add(username, CurrentCallback);
                    }
                }
            }
        }