public string GetPassword(string userName)
 {
     using (DienThoaiDBEntities db = new DienThoaiDBEntities())
     {
         return(db.Table_User.Where(x => x.UserName == userName).FirstOrDefault().UserPassword);
     }
 }
 //lay danh sach hang san xuat
 public List <HangSanXuat> GetListHangSanXuat()
 {
     using (DienThoaiDBEntities db = new DienThoaiDBEntities())
     {
         return(db.HangSanXuats.ToList());
     }
 }
 public bool IsExitstUserName(string userName)
 {
     using (DienThoaiDBEntities db = new DienThoaiDBEntities())
     {
         return(db.Table_User.Where(x => x.UserName == userName).Any());
     }
 }
 //lay danh sach dien thoai
 public List <DienThoai> GetListDT()
 {
     using (DienThoaiDBEntities db = new DienThoaiDBEntities())
     {
         return(db.DienThoais.ToList());
     }
 }
 public List <DienThoai> GetListDT_Category(int?id) //id la ma nha san xuat
 {
     if (id != null)
     {
         using (DienThoaiDBEntities db = new DienThoaiDBEntities())
         {
             return(db.DienThoais.Where(x => x.MaHDT == id).ToList());
         }
     }
     else
     {
         return(null);
     }
 }
 //lay hang San Xuat cua  Dien thoai
 public HangSanXuat GetHangSanXuat(int?id)
 {
     if (id != null)
     {
         using (DienThoaiDBEntities db = new DienThoaiDBEntities())
         {
             return(db.DienThoais.Find(id).HangSanXuat);
         }
     }
     else
     {
         return(null);
     }
 }
 //lay dien thoai vs ma id
 public DienThoai GetDienThoai(int?id)
 {
     if (id != null)
     {
         using (DienThoaiDBEntities db = new DienThoaiDBEntities())
         {
             return(db.DienThoais.Find(id));
         }
     }
     else
     {
         return(null);
     }
 }
 public bool AddUser(Table_User user)
 {
     using (DienThoaiDBEntities db = new DienThoaiDBEntities())
     {
         using (var trans = db.Database.BeginTransaction())
         {
             try
             {
                 db.Table_User.Add(user);
                 db.SaveChanges();
                 trans.Commit();
                 return(true);
             }
             catch
             {
                 trans.Rollback();
                 return(false);
             }
         }
     }
 }