用Asp隱藏檔案路徑，實現防盜鏈

    我們在管理網站檔案時，可以把副檔名一樣的檔案放在同一個目錄下，起一個比較特別名字，例如放pdf檔案目錄為the_pdf_file_s，把下面代碼另存新檔down.asp，他的網上路徑為http://www.xx.com/down.asp，我們就可以用http://www.xx.com/down.asp?FileName=51windows.pdf來下載這個檔案了，而且下載者無法看到這個檔案實際下載路徑的！在down.asp中我們還可以設定下載檔案是否需要登陸，判斷下載的來源頁是否為外部網站，從而可以做到防止檔案被盜鏈。 [來源：飛騰設計網www.feitec.com內容，轉載請註明出處]

    範例程式碼： [來源：飛騰設計網www.feitec.com內容，轉載請註明出處]

    <%
    From_url = Cstr(Request.ServerVariables("HTTP_REFERER"))
    Serv_url = Cstr(Request.ServerVariables("SERVER_NAME"))
    if mid(From_url,8,len(Serv_url)) <> Serv_url then
    response.write "非法連結！" '防止盜鏈
    response.end
    end if
    if Request.Cookies("Logined")="" then
    response.redirect "/login.asp" '需要登陸！
    end if
    Function GetFileName(longname)'/folder1/folder2/file.asp=>file.asp
    while instr(longname,"/")
    longname = right(longname,len(longname)-1)
    wend
    GetFileName = longname
    End Function

    Dim Stream
    Dim Contents
    Dim FileName
    Dim TrueFileName
    Dim FileExt
    Const adTypeBinary = 1
    FileName = Request.QueryString("FileName")
    if FileName = "" Then
    Response.Write "無效/webpage/asp/041101/24.htm！"
    Response.End
    End if

    FileExt = Mid(FileName, InStrRev(FileName, ".") + 1)
    Select Case UCase(FileExt)
    Case "ASP", "ASA", "ASPX", "ASAX", "MDB"
    Response.Write "非法操作！"
    Response.End
    End Select

    Response.Clear

    if lcase(right(FileName,3))="gif" or lcase(right(FileName,3))="jpg" or lcase(right(FileName,3))="png" then
    Response.ContentType = "image/*" '對影像檔不出現下載對話方塊
    else
    Response.ContentType = "application/ms-download"
    end if

    Response.AddHeader "content-disposition", "attachment; 200497141230.htm=" & GetFileName(Request.QueryString("FileName"))
    Set Stream = server.CreateObject("ADODB.Stream")
    Stream.Type = adTypeBinary
    Stream.Open
    if lcase(right(FileName,3))="pdf" then '設定pdf類型檔案目錄
    TrueFileName = "/the_pdf_file_s/"&FileName
    end if
    if lcase(right(FileName,3))="doc" then '設定DOC類型檔案目錄
    TrueFileName = "/my_D_O_C_file/"&FileName
    end if
    if lcase(right(FileName,3))="gif" or lcase(right(FileName,3))="jpg" or lcase(right(FileName,3))="png" then
    TrueFileName = "/all_images_/"&FileName '設定影像檔目錄
    end if
    Stream.LoadFromFile Server.MapPath(TrueFileName)
    While Not Stream.EOS
    Response.BinaryWrite Stream.Read(1024 * 64)
    Wend
    Stream.Close
    Set Stream = Nothing
    Response.Flush
    Response.End
    %>