private void cmdThemNguoiPhong_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                HyperlinkButton cmdThemNguoiPhong = (HyperlinkButton)sender;
                List<Nguoi_PhongInfo> ListNguoiPhong = new List<Nguoi_PhongInfo>();
                ListNguoiPhong = (List<Nguoi_PhongInfo>)grvTheoSoNguoi.ItemsSource;

                //add new row
                int Nguoi_PhongID = 0;
                Nguoi_PhongInfo NguoiPhong = null;
                if (cmdThemNguoiPhong.Content.Equals("Thêm"))
                {
                    if (NguoiPhongNextID != -1)
                    {
                        Nguoi_PhongID = NguoiPhongNextID;
                    }
                    NguoiPhong = new Nguoi_PhongInfo();
                    NguoiPhong.Nguoi_PhongID = Nguoi_PhongID;
                    NguoiPhong.NguoiPhongName = "";
                    NguoiPhong.CongThem = "";
                    NguoiPhong.ImageUrl = "Xóa";
                    ListNguoiPhong.Add(NguoiPhong);
                }
                else
                {
                    Nguoi_PhongID = int.Parse(cmdThemNguoiPhong.CommandParameter.ToString());
                    for (int i = 0; i < ListNguoiPhong.Count; i++)
                    {
                        if (ListNguoiPhong[i].Nguoi_PhongID == Nguoi_PhongID)
                        {
                            ListNguoiPhong.RemoveAt(i);
                            break;
                        }
                    }
                }
                NguoiPhongNextID = Nguoi_PhongID + 1;
                grvTheoSoNguoi.ItemsSource = null;
                grvTheoSoNguoi.ItemsSource = ListNguoiPhong;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
 protected void Nguoi_Phong_Load()
 {
     try
     {
         //Tao Du Lieu Trong
         List<Nguoi_PhongInfo> GioPhong = new List<Nguoi_PhongInfo>();
         Nguoi_PhongInfo Item = new Nguoi_PhongInfo();
         Item.Nguoi_PhongID = 1;
         Item.NguoiPhongName = "1";
         Item.GiaTien = 0;
         Item.PhanTram = 0;
         Item.CongThem = "";
         Item.ImageUrl = "Thêm";
         GioPhong.Add(Item);
         NguoiPhongNextID = 2;
         grvTheoSoNguoi.ItemsSource = GioPhong;
         txtCongThem.Text = "";
     }
     catch (Exception)
     {
         throw;
     }
 }