<%

Dim  fullName, s, fs, fl, Filesize, Filename, currentPath, relativePath

'取得文件名参数，可以是表单提交或者查询字符串

fullName = Request.QueryString("down")

If fullName = "" Then Call ShowMessage("对不起，文件名为空！")

'转为绝对路径

'该门课件的根路径

currentPath = Request.ServerVariables("PATH_TRANSLATED")

currentPath = Replace(currentPath,"script/download.asp","")

'网站子路径，为空代表下载文件直接放在根路径，可以添加子路径如"down/"

relativePath = "stream_db/"

'下载文件的完全路径

Filename = currentPath&relativePath&fullName

'检查文件是否存在

Set fs = Server.CreateObject("Scripting.FileSystemObject")

'If Not fs.FileExists(Filename) Then Call ShowMessage("对不起，指定文件不存在！")

'取得文件大小，单位是字节

Set fl = fs.GetFile(Filename)

Filesize = fl.Size

'销毁FSO对象

Set fl = Nothing

Set fs = Nothing

'清理缓存

Response.Buffer = True

Response.Clear

'创建Stream对象

Set s = Server.CreateObject("ADODB.Stream")

s.Open

'设置为二进制方式

s.Type = 1

'容错

On Error Resume Next

'装载文件

s.LoadFromFile (Filename)

If Err Then Call ShowMessage("装载指定文件出现未知错误！")

'向浏览器输出头部

Response.AddHeader "Content-Disposition", "attachment; filename="&fullName

Response.AddHeader "Content-Length",Filesize

'Response.CharSet="UTF-8"

Response.ContentType = "application/octet-stream"

'分段向浏览器输出文件

Do While Not s.EOS

Contents = s.Read (4096) '每次读取4096KB

Response.BinaryWrite Contents

Response.Flush

Loop

'一次性向浏览器输出文件

'Response.BinaryWrite s.Read

'Response.Flush

'销毁对象

s.Close: Set s = Nothing

'在本页输出提示信息

Sub ShowMessage(msg)

 Response.Write "<br><div align='center'><div style='color:red; font-weight:bold; text-align:center; border:1px solid #CCCCCC; 'background-color:#E8E8E8; padding:4px 2px 2px; width:300px; font-size:12px'>" & msg & "</div></div><br>"

 Response.End

End Sub

%>