public VanDongVien(VanDongVien vdv)
 {
     this.ThoiGianBatDau  = vdv.ThoiGianBatDau;
     this.ThoiGianKetThuc = vdv.ThoiGianKetThuc;
     this.MaSo            = vdv.MaSo;
     this.HoTen           = vdv.HoTen;
     this.SoAo            = vdv.SoAo;
 }
 public void Nhap_ThongTin_ListVanDongVien()
 {
     Console.Write("Nhap so luong van dong vien: ");
     this.SoLuong = int.Parse(Console.ReadLine());
     for (var i = 0; i < this.SoLuong; i++)
     {
         VanDongVien vdv = new VanDongVien();
         vdv.Nhap_ThongTin_VanDongVien();
         Them_VanDongVien(vdv);
     }
 }
 public void Them_VanDongVien(VanDongVien vdv)
 {
     List_VDV.Add(vdv);
 }