void laythongtin()
{
QLThuebaoDomainContext dbs = new QLThuebaoDomainContext();
EntityQuery<nhanvien_cs> Query = dbs.Getnhanvien_csQuery();
LoadOperation<nhanvien_cs> Load = dbs.Load(Query.Where(p => p.ma_huyen == App.ma_huyen && p.kt==App.kythuat), lo => { gridControl1.ItemsSource = lo.Entities; }, null);
}