asp驗證碼產生程式

//原創:www.111cn.net

註明:轉載請註明www.111cn.net

//

下面來說說asp程式產生驗證的方法.

<%
Option Explicit
Response.buffer=true
NumCode
dim znum
Function NumCode()
        Response.Expires = -1
        Response.AddHeader "Pragma","no-cache"
        Response.AddHeader "cache-ctrol","no-cache"
        dim zNum,i,j
        dim Ados,Ados1
        Randomize timer
        zNum = cint(8999*Rnd+1000)
        Session("ver") = zNum '把驗證碼寫入SESSION裡
        dim zimg(4),NStr
                NStr=cstr(zNum)
                For i=0 to 3
                        zimg(i)=cint(mid(NStr,i+1,1))
                Next
        dim Pos
        set Ados=Server.CreateObject("Adodb.Stream")
                Ados.Mode=3
                Ados.Type=1
                Ados.Open
        set Ados1=Server.CreateObject("Adodb.Stream")
                Ados1.Mode=3
                Ados1.Type=1
                Ados1.Open
                Ados.LoadFromFile(Server.mappath("body.Fix"))
                Ados1.write Ados.read(1280)
                for i=0 to 3
                        Ados.Position=(9-zimg(i))*320
                        Ados1.Position=i*320
                        Ados1.write ados.read(320)
                next       
                Ados.LoadFromFile(Server.mappath("head.fix"))
                Pos=lenb(Ados.read())
                Ados.Position=Pos
                for i=0 to 9 step 1
                        for j=0 to 3
                                Ados1.Position=i*32+j*320
                                Ados.Position=Pos+30*j+i*120
                                Ados.write ados1.read(30)
                        next
                next
                Response.ContentType = "image/BMP"
                Ados.Position=0
                Response.BinaryWrite Ados.read()
                Ados.Close:set Ados=nothing
                Ados1.Close:set Ados1=nothing
End Function
%>

在要調用的頁面aaa.htm<img src='ver.asp'/>這樣就行了,

驗證時就要判斷使用者輸入的是否與session("ver")相等就行了.