using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.IO;

public partial class _Default : System.Web.UI.Page

{

 protected void Page_Load(object sender, EventArgs e)

 {

 }

//TransmitFile实现下载

protected void Button1_Click(object sender, EventArgs e)

{

 Response.ContentType = "application/x-zip-compressed";

 Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");

 string filename = Server.MapPath("DownLoad/z.zip");

 Response.TransmitFile(filename);

}

//WriteFile实现下载

protected void Button2_Click(object sender, EventArgs e)

{

 string fileName ="asd.txt";//客户端保存的文件名

 string filePath=Server.MapPath("DownLoad/aaa.txt");//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.txt";//客户端保存的文件名

 string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

 System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);

if (fileInfo.Exists == true)

{

 const long ChunkSize = ;//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(fil  eName));

  while (dataLengthToRead >  && Response.IsClientConnected)

  {

 int lengthRead = iStream.Read(buffer, , Convert.ToInt32(ChunkSize));//读取的大小

 Response.OutputStream.Write(buffer, , lengthRead);

 Response.Flush();

 dataLengthToRead = dataLengthToRead - lengthRead;

}

 Response.Close();

}

}

//流方式下载

protected void Button4_Click(object sender, EventArgs e)

{

 string fileName = "aaa.txt";//客户端保存的文件名

 string filePath = Server.MapPath("DownLoad/aaa.txt");//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, , 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(fi  leName, System.Text.Encoding.UTF8));

 Response.BinaryWrite(bytes);

 Response.Flush();

 Response.End();

}

}