private void btn_edit_ItemClick(object sender, ItemClickEventArgs e)
        {
            var maMH     = gridView1.GetFocusedRowCellValue("MaHang").ToString();
            var tenMH    = gridView1.GetFocusedRowCellValue("TenMatHang").ToString();
            var DVT      = gridView1.GetFocusedRowCellValue("DVT").ToString();
            var maLoaiMH = gridView1.GetFocusedRowCellValue("MaLoaiMatHang").ToString();
            var giaban   = gridView1.GetFocusedRowCellValue("GiaBan").ToString();
            var gianhap  = gridView1.GetFocusedRowCellValue("GiaNhap").ToString();
            var maNCC    = gridView1.GetFocusedRowCellValue("MaNhaCC").ToString();
            var tgBH     = gridView1.GetFocusedRowCellValue("BaoHanh").ToString();
            frm_MatHang_SuaMatHang frm = new frm_MatHang_SuaMatHang(maMH, tenMH, maLoaiMH, DVT, giaban, gianhap, maNCC, tgBH);

            frm.ShowDialog();
            refress();
        }
        private void barButtonItem3_ItemClick(object sender, ItemClickEventArgs e)
        {
            frm_MatHang_SuaMatHang frm = new frm_MatHang_SuaMatHang();

            frm.ShowDialog();
        }