//Nút sửa
        private void btnSua_Click(object sender, RoutedEventArgs e)
        {
            #region 1. Lấy thông tin
            DataRowView     _drv = (DataRowView)dgKhachHang.SelectedItem;
            KhachHangPublic _kh  = new KhachHangPublic();
            _kh.MaKH_KH          = _drv["MaKH_KH"].ToString();
            _kh.HoTen_KH         = _drv["HoTen_KH"].ToString();
            _kh.GioiTinh_KH      = _drv["GioiTinh_KH"].ToString();
            _kh.NgaySinh_KH      = Convert.ToDateTime(_drv["NgaySinh_KH"].ToString());
            _kh.Email_KH         = _drv["Email_KH"].ToString();
            _kh.NHK_KH.MaNKH_NKH = _drv["Ma_NHK_KH"].ToString();
            _kh.DiemTichLuy_KH   = Convert.ToInt32(_drv["DiemTichLuy_KH"].ToString());
            _kh.SoLanMuaHang_KH  = Convert.ToInt32(_drv["SoLanMuaHang_KH"].ToString());
            _kh.SDT_KH           = _drv["SDT_KH"].ToString();
            _kh.GhiChu           = _drv["GhiChu_KH"].ToString();
            _kh.TuDongLenNhom_KH = (bool)_drv["TuDongLenNhom_KH"];
            _kh.DangDung_KH      = (bool)_drv["DangDung_KH"];
            #endregion

            #region 2. Hiển thị wpf sửa
            KhachHangSuaPresentation wpf = new KhachHangSuaPresentation();
            wpf._kh            = _kh;
            wpf._SuaKhachhang += new EventHandler(SuaKhachHang);
            wpf.ShowDialog();
            #endregion
        }
        //Phương thức sửa khách hàng
        void SuaKhachHang(object sender, EventArgs e)
        {
            #region 1. Lấy thông tin
            KhachHangSuaPresentation wpf = (KhachHangSuaPresentation)sender;
            KhachHangPublic          _kh = wpf._kh;
            #endregion

            #region 2. Lưu vào csdl
            if (KhachHangBusiness.SuaKhachHang(_kh))
            {
                LoadDataToDataGrid();
            }
            else
            {
                MessageBox.Show("Sửa thông tin khách hàng thất bại");
            }
            #endregion
        }