private void BtnLogin_Click(object sender, RoutedEventArgs e)
        {
            var user = DataAccess.GetAllUsers().FirstOrDefault(x => x.Username.ToLower() == this.TxtUsername.Text.ToLower());

            if (String.IsNullOrEmpty(this.TxtUsername.Text) || String.IsNullOrEmpty(this.TxtPassword.Password))
            {
                MessageBox.Show("Username or password empty!");
            }
            else if(user != null && PasswordHash.ValidatePassword(this.TxtPassword.Password,user.PasswordHash))
            {
                if (user.IsAdmin)
                {
                    AdminLoggedIn window = new AdminLoggedIn();
                    this.Close();
                    window.ShowDialog();
                }
                else
                {
                    UserLoggedIn window = new UserLoggedIn();
                    this.Close();
                    window.ShowDialog();
                }
            }
            else
            {
                MessageBox.Show("Username or password is incorrect!");
            }
        }
 public AddCity(ref AdminLoggedIn parent)
 {
     this.InitializeComponent();
     this.parent = parent;
 }