private void BtnExport_Click(object sender, EventArgs e)
{
ExportToExcel excel = new ExportToExcel();
string query = "SELECT * FROM dbo.CTHDNhap";
System.Data.DataTable data = DataProvider.Instance.ExecuteQuery(query);
excel.ExportCTHDNhap(data, "Danh sach CTHDNhap", "HÓA ĐƠN NHẬP: " + maHDNhap);
}
