File Download by ASP Stream文件流下载功能

<%@LANGUAGE="VBSCRIPT" CODEPAGE="936"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />

<title>无标题文档</title>

</head>



<body>



<%

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

%>





</body>

</html>







本文来自CSDN博客,转载请标明出处:http://blog.csdn.net/maxgong2005/archive/2006/09/01/1154388.aspx

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