public DataTable F_LoadHoaDon(int MaDonHang) { var a = from p in dbs.F_LoadHoaDon(MaDonHang) select p; if (a != null) { SqlCommand cmd = (SqlCommand)dbs.GetCommand(a); DataTable dt = new DataTable(); SqlDataAdapter da = new SqlDataAdapter(cmd); da.Fill(dt); return(dt); } else { return(null); } }