C# code

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

=

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();

}

}