asp.net文件下载

    //TransmitFile实现下载
         protected void Button1_Click1(object sender, EventArgs e)
        {
            /*
             微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite
             下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。
             代码如下：
             */
            string strFileName = "三部闲置设备管理系统操作手册IEMS.ppt";
            Response.ContentType = "application/x-zip-compressed";
            //Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            string filename = BLL.Config.PART_EM_UPLOAD_DOC + strFileName;
            //BLL.Config.PART_EM_UPLOAD_DOC 为路径   ("D:/EMUploadDoc/")
            Response.AddHeader("Content-Disposition", "attachment;filename=" +Server.UrlPathEncode(strFileName));
           //Server.UrlPathEncode()解决文件名的乱码问题.
           
            Response.TransmitFile(filename);
        }    //WriteFile实现下载
    protected void Button2_Click(object sender, EventArgs e)
&