Web导出Excel：无COM组件依赖方法

    //======调用实列====================    
  //导出Excel
    protected void btn_DownLoadExcel_Click(object sender, EventArgs e)
    {
        string path = "路径/" + DateTime.Now.ToString("yyyyMMddHHmmss")+".xml";
        string fileName = "*.xls";//下载的文件名
        DataTable dt = //要导出的数据;

        if (null != dt)
        {
            try
            {
                DownFileByExcel(path, dt, fileName);//调用方法
            }
            catch (Exception ex)
            {
                //弹出异常                
            }

        }
        else
        {
            //dataTable is null
        }

    }

    //======方法===============
    /// <summary>
    /// 导出Excel以XML型式

    /// </summary>
    /// <param name="path">相对路径</param>
    /// <param name="dt">数据</param>
    /// <param name="fileName">下载的文件名</param>
    public void DownFileByExcel(string path, DataTable dt, string fileName)
    {
        DownLoad dl = new DownLoad();
        dl.WriteDataToExcel(dt, Server.MapPath(path));
        this.DownFileName(Server.MapPath(path), fileName);
    }

   //下载文件
    private void DownFileName(string fileName, string downFileName)
    {

        Response.Clear();
        Response.Buffer = true;
        //设置输出流的HTTP字符集
        Response.Charset = "utf-8";
        string attachment = "attachment; filename=" + HttpUtility.UrlEncode(downFileName, System.Text.Encoding.UTF8);
        Response.AddHeader("content-disposition", attachment);
        Response.ContentType = "application/octent-stream";
        Response.WriteFile(fileName);
        Response.End();
    }

 #region  写Excle 的XML格式  这只是一个基本实例，具体可以自己修改
        private void WriteDataToExcel(System.Data.DataTable dt, string path)
        {
            int rowNum = dt.Rows.Count; //行数