using System;

using System.Data;

using System.Configuration;

using System.IO;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;



/// <summary>

/// 

/// </summary>

public class GridViewExportUtil

{

    /// <summary>

    /// 

    /// </summary>

    /// <param name="fileName"></param>

    /// <param name="gv"></param>

    public static void Export(string fileName, GridView gv)

    {

        HttpContext.Current.Response.Clear();

        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 form to contain the grid

                Table table = new Table();



                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);



                //  render the htmlwriter into the response

                HttpContext.Current.Response.Write(sw.ToString());

                HttpContext.Current.Response.End();

            }

        }

    }



    /// <summary>

    /// Replace any of the contained controls with literals

    /// </summary>

    /// <param name="control"></param>

    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"));

            }



            if (current.HasControls())

            {

                GridViewExportUtil.PrepareControlForExport(current);

            }

        }

    }

}