public static void ExportExcel(BandedGridView ip_grv)
 {
     SaveFileDialog saveFileDialog1 = new SaveFileDialog();
     saveFileDialog1.Filter = "xls files (*.xls)|*.xls|All files (*.*)|*.*";
     saveFileDialog1.RestoreDirectory = true;
     if(saveFileDialog1.ShowDialog() == DialogResult.OK)
     {
         ip_grv.ExportToXls(saveFileDialog1.FileName);
         DevExpress.XtraEditors.XtraMessageBox.Show("Trích xuất dữ liệu thành công!", "THÔNG BÁO", MessageBoxButtons.OK, MessageBoxIcon.Information);
     }
 }