NET可用的下载方式（包含下载统计）：

下载的同时记录下载次数，不能用超链接直接下载，而应该用超链接跳到一个aspx中间页 面，并在这个页面的CS文件中Page_Load方法中，用Response.Redirect("url");指向下载的文件。这样点击下载后，客户看 到的一直是下载页面，不会看到中间页面。

1、<a href="mp3/生命的希望不再失落.mp3">下载</a>

2、Response.Redirect("mp3/生命的希望不再失落.mp3");

3、Server.Transfer("mp3/生命的希望不再失落.mp3");

4、流方式：网上的四种方法如下

// TransmitFile实现下载
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/z.zip " );
Response.TransmitFile(filename);
}

// WriteFile实现下载
protected void Button2_Click( object sender, EventArgs e)
{
/*
using System.IO;

*/
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 = 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 > 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.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, 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();
}



// ----------------------------------------------------------





public void DownloadFile( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FileBody )
{

　　WebForm.Response.ClearHeaders();
　　WebForm.Response.Clear();
　　WebForm.Response.Expires = 0 ;
　　WebForm.Response.Buffer = true ;
　　WebForm.Response.AddHeader( " Accept-Language " , " zh-tw " );
　　 // '文件名称
　　WebForm.Response.AddHeader( " content-disposition " , " attachment; filename=' " + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) + " ' " );
　　WebForm.Response.ContentType = " Application/octet-stream " ;
　　 // '文件内容
　　WebForm.Response.Write(FileBody); // -----------
WebForm.Response.End();
}


// 上面这段代码是下载一个动态产生的文本文件，若这个文件已经存在于服务器端的实体路径，则可以通过下面的函数：

public void DownloadFileByFilePath( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FilePath )
{
　　WebForm.Response.ClearHeaders();
　　WebForm.Response.Clear();
　　WebForm.Response.Expires = 0 ;
WebForm.Response.Buffer = true ;
　　WebForm.Response.AddHeader( " Accept-Language " , " zh-tw " );
　　 // 文件名称
　　WebForm.Response.AddHeader( " content-disposition " , " attachment; filename=' " + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) + " ' " );
　　WebForm.Response.ContentType = " Application/octet-stream " ;
　　 // 文件内容
　　WebForm.Response.Write(System.IO.File.ReadAllBytes(FilePath)); // ---------
　　WebForm.Response.End();
}