原作:possible_Y,載自時(shí)代課堂

在瀏覽器的地址欄里直接輸入一個(gè)doc或xls或jpg的文件的url路徑，那么該文件會(huì)直接顯示在瀏覽器里。而在很多時(shí)候我們希望能直接彈出下載提示框讓用戶下載，我們?cè)撛趺崔k呢？這里有兩種方法：
1、設(shè)置你的服務(wù)器的iis，給doc等后綴名做映射
2、在向客戶端發(fā)送時(shí)設(shè)置其contenttype

下面詳細(xì)說(shuō)明方法2

<%
Response.Buffer = true
Response.Clear

dim url
Dim fso,fl,flsize
dim Dname
Dim objStream,ContentType,flName,isre,url1
'*********************************************調(diào)用時(shí)傳入的下載文件名
Dname=trim(request("n"))
'******************************************************************
If Dname<>"" Then
'******************************下載文件存放的服務(wù)端目錄
 url=server.MapPath("/")&"/"&Dname
'***************************************************
End If

Set fso=Server.CreateObject("Scr Set fl=fso.getfile(url)
 flsize=fl.size
 flName=fl.name
 Set fl=Nothing
 Set fso=Nothing
%>
<%
 Set objStream = Server.CreateObject("ADODB.Stream")
 objStream.Open
 objStream.Type = 1
 objStream.LoadFromFile url

  Select Case lcase(Right(flName, 4))
  Case ".asf"
   ContentType = "video/x-ms-asf"
  Case ".avi"
   ContentType = "video/avi"
  Case ".doc"
   ContentType = "application/msWord"
  Case ".zip"
   ContentType = "application/zip"
  Case ".xls"
   ContentType = "application/vnd.ms-Excel"
  Case ".gif"
   ContentType = "image/gif"
  Case ".jpg", "jpeg"
   ContentType = "image/jpeg"
  Case ".wav"
   ContentType = "audio/wav"
  Case ".mp3"
   ContentType = "audio/mpeg3"
  Case ".mpg", "mpeg"
   ContentType = "video/mpeg"
  Case ".rtf"
   ContentType = "application/rtf"
  Case ".htm", "html"
   ContentType = "text/html"
  Case ".txt"
   ContentType = "text/plain"
  Case Else
   ContentType = "application/octet-stream"
  End Select

  Response.AddHeader "Content-Disposition", "attachment; filename=" & flName
  Response.AddHeader "Content-Length", flsize

  Response.Charset = "UTF-8"
  Response.ContentType = ContentType

  Response.BinaryWrite objStream.Read
  Response.Flush
  response.Clear()
 objStream.Close
 Set objStream = Nothing

%>

將下面的東西存成download.asp然后你就可以用<a herf="http://www.survivalescaperooms.com/download.asp?n=file.doc">download!</a>來(lái)下載同一目錄下的file.doc了!

但是這里有個(gè)問(wèn)題就是直接將file.doc路徑寫(xiě)在url里是不安全的，所以解決方案應(yīng)該是將file.doc的路徑存到數(shù)據(jù)庫(kù)里，同過(guò)查找數(shù)據(jù)庫(kù)后得到路徑

在這個(gè)程序的最前面如果加上一個(gè)判斷：

if instr(Request.ServerVariables("HTTP_REFERER"),"http://你的域名")=0 then
  Response.End
end if

就能夠很好的防止別人的盜鏈了