private void txtTimKiem_KeyUp(object sender, KeyEventArgs e)
 {
     try
     {
         if (e.KeyCode == Keys.Enter)
         {
             if (bool.Parse(radioGroup1.EditValue.ToString()))//tim theo ten
             {
                 gridControlGV.DataSource = GiangVienBUS.DanhSachGiangVien().Where(gv => gv.HoTen.ToLower().Contains(txtTimKiem.Text.Trim().ToLower()));
             }
             else if (txtTimKiem.Text.Trim().Length == 6)//tim theo ma
             {
                 gridControlGV.DataSource = GiangVienBUS.DanhSachGiangVien().Where(gv => gv.MaGV.ToLower() == txtTimKiem.Text.Trim().ToLower());
             }
             else
             {
                 MsgboxUtil.Exclamation("Mã giảng viên không đúng định dạng");
             }
         }
     }
     catch (Exception ex)
     {
         ExceptionUtil.ThrowMsgBox(ex.Message);
     }
 }
 private void LoadSourceGiangVien()
 {
     try
     {
         giangVien = GiangVienBUS.DanhSachGiangVien();
         gridControlGV.DataSource = giangVien;
     }
     catch (Exception ex)
     {
         throw ex;
     }
 }