asp实现图片防盗链

有时我们不想让别的网站转载自己网站的图片，当别人转载时用另外一张图片代替，想必这样的功能大家都见到过，其实在asp里也很容易实现这样的图片防盗链功能，下面通过一个简单的代码来说明防盗链的原理：

getimage.asp
<% Option Explicit

Dim strBuffer, FilePath
strBuffer = Request.ServerVariables("HTTP_REFERER")
strBuffer = mid(strBuffer, InStr(strBuffer,".") + 1)
strBuffer = left(strBuffer, InStr(strBuffer, "/") - 1)

FilePath = "/HIDDENIMAGES/"

If strBuffer = "www.bhcode.net" then
FilePath = FilePath + Request.QueryString("FName")
Else
FilePath = "/images/chunfeng.jpg"
End If

Response.Redirect(FilePath)
%>