using System.Data;

using System.IO;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

/// <summary>

/// 导出EXCEL

/// </summary>

public class GridViewExportUtil

{

    /// <summary>

    /// 将GRIDVIEW导出excel

    /// </summary>

    /// <param name="fileName">excel文件名</param>

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

    public static void Export(string fileName, GridView gv)

    {

        HttpContext.Current.Response.Clear();

        //HttpContext.Current.Response.Charset = "GB2312";

        //HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");

        HttpContext.Current.Response.AddHeader(

            "content-disposition", string.Format("attachment; filename={0}", fileName));

        HttpContext.Current.Response.ContentType = "application/ms-excel";

        HttpContext.Current.Response.Write("<meta http-equiv=Content-Type content=\"text/html; charset=utf-8\">");

        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;

                //table.BackColor = gv.BackColor;

                //  add the header row to the table

                if (gv.HeaderRow != null)

                {

                    GridViewExportUtil.PrepareControlForExport(gv.HeaderRow);

                    table.Rows.Add(gv.HeaderRow);

                    table.Rows[].BackColor = System.Drawing.Color.Black;

                    table.Rows[].ForeColor = System.Drawing.Color.White;

                    table.Rows[].Height = Unit.Pixel();

                }

                //  add each of the data rows to the table

                foreach (GridViewRow row in gv.Rows)

                {

                    GridViewExportUtil.PrepareControlForExport(row);

                    row.Height = Unit.Pixel();

                    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();

            }

        }

    }

    public static void Export(string fileName, DataTable dt)

    {

        using (GridView gv = new GridView())

        {

            gv.DataSource = dt;

            gv.DataBind();

            Export(fileName, gv);

        }

    }

    /// <summary>

    /// Replace any of the contained controls with literals

    /// </summary>

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

    private static void PrepareControlForExport(Control control)

    {

        for (int i = ; 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);

            }

        }

    }

}