扩展GridView导出Excel功能

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Web;
using System.Web.Compilation;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Web
{
    //作者：林宏权 2015/12/31 00:16

/// <summary>
    /// 扩展GridView导出Excel功能
    /// </summary>
    public partial class ExportGridView : GridView
    {
        /// <summary>
        /// 数据库连接字符串
        /// </summary>
        public string ConnectionString { get; set; }
        /// <summary>
        /// 命令文本
        /// </summary>
        public string SqlCmdText { get; set; }
        /// <summary>
        /// 主键字段
        /// </summary>
        public string[] PrimaryKey { get; set; }
        /// <summary>
        /// 导出的Excel文件名
        /// </summary>
        public string ExcelFileName { get; set; }
        /// <summary>
        /// 导出分页数据
        /// </summary>
        public bool ExportPagging { get; set; }

public ExportGridView()
        {
        }

public ExportGridView(string connectString,string cmd,string[] keys)
        {
            //启用分页
            AllowPaging = true;
            //启用排序
            AllowSorting = true;
            //数据源
            DataSource = new SqlDataSource(connectString, cmd);
            //主键字段
            DataKeyNames = keys;
            //导出分页数据(默认导出分页数据)
            ExportPagging = true;
        }

/// <summary>
        /// 网页表格导出到Excel文件f
        /// </summary>
        /// <param name="fileName">导出的文件名</param>
        public  void GridViewToExcel( string fileName)
        {
            //启用分页
            AllowPaging = false;
            //启用排序
            AllowSorting = false;
            //重新绑定数据源
            DataBind();
            //字符集编码
            HttpContext.Current.Response.Charset = "GB2312";
            //内容编码
            HttpContext.Current.Response.ContentEncoding = Encoding.UTF8;
            //文件名编码
            var fileNameUtf8 = HttpUtility.UrlEncode(fileName, Encoding.UTF8);
            //添加Http头输出
            HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + fileNameUtf8);
            //输出MIME类型
            HttpContext.Current.Response.ContentType = "application/ms-excel";
            //关闭页面与服务器控件的视图状态
            EnableViewState = false;
            //输出服务器控件(GridView)的内容到HtmlTextWriter
            //==============================================
            StringWriter tw = new StringWriter();
            HtmlTextWriter hw = new HtmlTextWriter(tw);
            RenderControl(hw);
            //==============================================
            //http输出(Excel)文件
            HttpContext.Current.Response.Write(tw.ToString());
            //发送到客户端
            HttpContext.Current.Response.End();
        }
    }
}