asp.net下载的几种常用的方式如下。在下载的时候，为了防止弹出窗口，可以采用在原页面加一个

<iframe id="iDownload" style="display:none;" ></iframe>

然后用jquery语句指定下载链接。

$("#iDownload").attr("src", "download.ashx?filename=" + encodeURI($(this).children("span").first().text()));

 

protected void Button1_Click(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：    */    Response.ContentType = "application/x-zip-compressed";    Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");    string filename = Server.MapPath("DownLoad/aaa.zip");    Response.TransmitFile(filename);    }

  //WriteFile实现下载    protected void Button2_Click(object sender, EventArgs e)    {    /*    using System.IO;    */    string fileName ="aaa.zip";//客户端保存的文件名    string filePath=Server.MapPath("DownLoad/aaa.zip");//路径    FileInfo fileInfo = new FileInfo(filePath);    Response.Clear();    Response.ClearContent();    Response.ClearHeaders();    Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);    Response.AddHeader("Content-Length", fileInfo.Length.ToString());    Response.AddHeader("Content-Transfer-Encoding", "binary");    Response.ContentType = "application/octet-stream";    Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");    Response.WriteFile(fileInfo.FullName);    Response.Flush();    Response.End();    }

  //WriteFile分块下载    protected void Button3_Click(object sender, EventArgs e)    {    string fileName = "aaa.zip";//客户端保存的文件名    string filePath = Server.MapPath("DownLoad/aaa.zip");//路径    System.IO.FileInfo fileInfo = new System.IO.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();    System.IO.FileStream iStream = System.IO.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 &gt; 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();    }    }

  //流方式下载    protected void Button4_Click(object sender, EventArgs e)    {    string fileName = "aaa.zip";//客户端保存的文件名    string filePath = Server.MapPath("DownLoad/aaa.zip");//路径    //以字符流的形式下载文件    FileStream fs = new FileStream(filePath, FileMode.Open);    byte[] bytes = new byte[(int)fs.Length];    fs.Read(bytes, 0, bytes.Length);    fs.Close();    Response.ContentType = "application/octet-stream";    //通知浏览器下载文件而不是打开    Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));    Response.BinaryWrite(bytes);    Response.Flush();    Response.End();    } 

本文转自cnn23711151CTO博客，原文链接： http://blog.51cto.com/cnn237111/699359，如需转载请自行联系原作者