private void SuaThongTinHocSinhForm_Load(object sender, EventArgs e) { tbHoTen.Text = hocSinhLogin.HoTen; dtpNgaySinh.Value = Convert.ToDateTime(hocSinhLogin.NgaySinh); tbDiaChi.Text = hocSinhLogin.DiaChi; List <Lop> dsLop = new List <Lop>(); dsLop = hocSinhBUS.LayDanhSachLop(); if (dsLop != null) { cbbLop.DataSource = dsLop; cbbLop.DisplayMember = "TenLop"; cbbLop.ValueMember = "MaLop"; cbbLop.Text = hocSinhLogin.MaLop; } else { cbbLop.Text = "Chưa có lớp nào phù hợp!"; } }