文件下载

  /// <summary>
    /// 文件下载
    /// </summary>
    /// <param name="filename"></param>
    public void DownFile(string filename)
    {
        FileInfo info = new FileInfo(Server.MapPath(filename));
        Response.Clear();
        Response.ClearContent();
        Response.ClearHeaders();
        string urlName = HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8);
        Response.AddHeader("Content-Disposition", "attachment;filename=" + urlName);
        Response.AddHeader("Content-Length", info.Length.ToString());
        Response.AddHeader("Content-Transfer-Encoding", "binary");
        Response.ContentType = "application/octet-stream";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
        Response.WriteFile(info.FullName);
        Response.Flush();
        Response.End();
    }