GridView를 excel 보조 클래스로 내보내기

class GridViewExportUtil
    {

        /// 

        /// 
        /// 
        /// 
        /// 
        public static void Export(string fileName, GridView gv, ArrayList Excludedcolumns)
        {
            //Columns' index arraylist (removeColumnslistIndex) of GridView gv
            if (Excludedcolumns != null)
            {
                for (int j = 0; j < Excludedcolumns.Count; j++)
                {
                    if (gv.HeaderRow != null)
                    {
                        gv.HeaderRow.Cells[Convert.ToInt32(Excludedcolumns[j])].Visible = false;
                    }

                    for (int i = 0; i < gv.Rows.Count; i++)
                    {
                        gv.Rows[i].Cells[Convert.ToInt32(Excludedcolumns[j])].Visible = false;
                    }

                    if (gv.FooterRow != null)
                    {
                        gv.FooterRow.Cells[Convert.ToInt32(Excludedcolumns[j])].Visible = false;
                    }
                }
            }
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.Charset = "Utf-8";
            HttpContext.Current.Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", fileName));
            HttpContext.Current.Response.ContentType = "application/ms-excel";

            using (StringWriter sw = new StringWriter())
            {
                using (HtmlTextWriter htw = new HtmlTextWriter(sw))
                {
                    //Create a table to contain the grid
                    Table table = new Table();
                    table.GridLines = GridLines.Both;

                    //include the gridline settings
                    //table.GridLines = gv.GridLines;

                    //add the header row to the table
                    if (gv.HeaderRow != null)
                    {
                        GridViewExportUtil.PrepareControlForExport(gv.HeaderRow);
                        table.Rows.Add(gv.HeaderRow);
                    }

                    //add each of the data rows to the table
                    foreach (GridViewRow row in gv.Rows)
                    {
                        GridViewExportUtil.PrepareControlForExport(row);
                        table.Rows.Add(row);
                    }

                    //add the footer row to the table
                    if (gv.FooterRow != null)
                    {
                        GridViewExportUtil.PrepareControlForExport(gv.FooterRow);
                        table.Rows.Add(gv.FooterRow);
                    }

                    //render the table into the htmlwriter
                    table.RenderControl(htw);

                    HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache);
                    //render the htmlwriter into the response
                    HttpContext.Current.Response.Write(sw.ToString());
                    HttpContext.Current.Response.End();
                }
            }
        }

        /// 

        /// Replace any of the contained controls with literals
        /// 
        /// 
        private static void PrepareControlForExport(Control control)
        {
            for (int i = 0; i < control.Controls.Count; i++)
            {
                Control current = control.Controls[i];
                if (current is LinkButton)
                {
                    control.Controls.Remove(current);
                    control.Controls.AddAt(i, new LiteralControl((current as LinkButton).Text));
                }
                else if (current is ImageButton)
                {
                    control.Controls.Remove(current);

                    control.Controls.AddAt(i, new LiteralControl((current as ImageButton).AlternateText));
                }
                else if (current is HyperLink)
                {
                    control.Controls.Remove(current);
                    control.Controls.AddAt(i, new LiteralControl((current as HyperLink).Text));
                }
                else if (current is DropDownList)
                {
                    control.Controls.Remove(current);
                    control.Controls.AddAt(i, new LiteralControl((current as DropDownList).SelectedItem.Text));
                }
                else if (current is CheckBox)
                {
                    control.Controls.Remove(current);
                    control.Controls.AddAt(i, new LiteralControl((current as CheckBox).Checked ? "True" : "False"));
                }
                else if (current is Menu)
                {

                    control.Controls.Remove(current);
                    control.Controls.AddAt(i, new LiteralControl((current as Menu).SelectedValue.ToString()));

                }
                else if (current is Microsoft.SharePoint.WebControls.Menu)
                {
                    control.Controls.Remove(current);
                    control.Controls.AddAt(i, new LiteralControl((current as Microsoft.SharePoint.WebControls.Menu).Text));
                }

                if (current.HasControls())
                {
                    GridViewExportUtil.PrepareControlForExport(current);
                }
            }
        }
    }