protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            if (Request.QueryString["filename"] != null && Request.QueryString["path"] != null)
            {
                string filename = Request.QueryString["filename"];
                string path = Request.QueryString["path"];
                if (!string.IsNullOrEmpty(filename))
                {
                    string filePath = Server.MapPath("~" + path) + filename;
                    FileInfo fileInfo = new FileInfo(filePath);

                    if (fileInfo.Exists == true)
                    {
                        const long ChunkSize = 102400;//100K 每次读取文件，只读取100K，这样可以缓解服务器的压力 
                        byte[] buffer = new byte[ChunkSize];

                        Response.Clear();
                        FileStream iStream = File.OpenRead(filePath);
                        long dataLengthToRead = iStream.Length;//获取下载的文件总大小 
                        Response.ContentType = "application/octet-stream";
                        Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(filename));
                        while (dataLengthToRead > 0 && Response.IsClientConnected)
                        {
                            int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小 
                            Response.OutputStream.Write(buffer, 0, lengthRead);
                            Response.Flush();
                            dataLengthToRead = dataLengthToRead - lengthRead;
                        }
                        Response.Close();
                    }
                }
            }
        }
    }

 

 

调用： lnk_down.HRef = "Download.aspx?filename=" + 文件名+ "&path=" + 文件路径;

本文转自94cool博客园博客，原文链接：http://www.cnblogs.com/94cool/archive/2011/08/02/2124978.html，如需转载请自行联系原作者