原作:possible_Y,載自時代課堂
在瀏覽器的網址列裡直接輸入一個doc或xls或jpg的文件的url路徑，那麼該文件會直接顯示在瀏覽器裡。而很多時候我們希望能直接彈出下載提示框讓使用者下載，我們該怎麼辦呢？這裡有兩種方法：
1.設定你的伺服器的iis，給doc等後綴名做映射
2.在傳送給客戶端時設定其contenttype
下面詳細說明方法2
<%
Response.Buffer = true
Response.Clear
dim url
Dim fso,fl,flsize
dim Dname
Dim objStream,ContentType,flName,isre,url1
'*********************************************調用時傳入的下載檔名
Dname=trim(request("n"))
'************************************************* *****************
If Dname<>"" Then
'******************************下載檔案存放的服務端目錄
url=server.MapPath("/")&""&Dname
'************************************************* **
End If
Set fso=Server.CreateObject("Scripting.FileSystemObject")
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然後你就可以用<a herf=" http://www.downcodes.com/download.asp?n=file.doc">download!</ a >來下載同一目錄下的file.doc了!
但是這裡有個問題就是直接將file.doc路徑寫在url裡是不安全的，所以解決方案應該是將file.doc的路徑存到資料庫裡，同過查找資料庫後得到路徑
在這個程式的最前面如果加上一個判斷：
if instr(Request.ServerVariables("HTTP_REFERER"),"http://你的網域名稱")=0 then
Response.End
end if
就能夠很好的防止別人的盜鏈了