一个超简单asp生成验证码程序

<%
sub getsafecode
 dim test,result
 on error resume next
 set test=server.createobject("adodb.stream")
 set test=nothing
 if err then
  dim znum
  randomize timer
  znum=cint(8999*rnd+1000)
  session("safecode")=znum
  result=session("safecode")
 else
  result="<img src="" safecode.asp"" align="" absmiddle"">"
 end if
 response.write result
end sub
%>

safecode.asp文件代码如下

<%

 dim objcanvas
 dim pointx,pointy,pointcolor
 dim itemp
 dim safecode
 dim r,g,b,cc,kk 
 cc=80
 kk=30
 safecode = ""
 session("safecode") = ""
 
 bgcolor = "ffffff"
 
 r = mid(bgcolor,1,2)
 g = mid(bgcolor,3,2)
 b = mid(bgcolor,5,2)
  
 
 
 r = dechex(r)
 g = dechex(g)
 b = dechex(b)
 
 set objcanvas = new canvas
 
 objcanvas.globalcolourtable(0) = rgb(255,255,255) ' white
 objcanvas.globalcolourtable(1) = rgb(0,0,0) ' black
 objcanvas.globalcolourtable(2) = rgb(255,0,0) ' red
 objcanvas.globalcolourtable(3) = rgb(0,255,0) ' green
 objcanvas.globalcolourtable(4) = rgb(0,0,255) ' blue
 objcanvas.globalcolourtable(5) = rgb(128,0,0)
 objcanvas.globalcolourtable(6) = rgb(0,128,0)
 objcanvas.globalcolourtable(7) = rgb(0,0,128)
 objcanvas.globalcolourtable(8) = rgb(128,128,0)
 objcanvas.globalcolourtable(9) = rgb(0,128,128)
 objcanvas.globalcolourtable(10) = rgb(128,0,128)
 objcanvas.globalcolourtable(11) = rgb(r,g,b)

 objcanvas.backgroundcolourindex = 11
 
 objcanvas.resize cc,kk,false 
 
 
 randomize timer
 safecode = cint(8999*rnd+1000) 
  
 for itemp = 0 to 30
  randomize timer
  pointx = int(rnd * cc)
  pointy = int(rnd * kk)
  pointcolor = int(rnd * 3)+2
  objcanvas.foregroundcolourindex = pointcolor  
  objcanvas.line pointx,pointy,pointx,pointy 
  
 next 
 
 objcanvas.foregroundcolourindex = 1
 objcanvas.line 1,1,cc,1
 objcanvas.line 1,kk,1,1
 objcanvas.line 1,kk,cc,kk
 objcanvas.line cc,1,cc,kk
 
 session("safecode") = safecode
 dim sc,sk
 randomize timer
 sc = cint(24*rnd)
 sk = cint(11*rnd)
 objcanvas.drawtextwe sc,sk,safecode
 objcanvas.write
  

 

function dechex (hstr)
 
 dim result
 dim i,l
 
 result = 0
 
 
 l = len(hstr)
 

 for i = l-1 to 0 step -1
 
  result = result + (16 ^ i)*getdecbit(mid(hstr,i+1,1))
  
 next
 
 dechex = result
 
end function

function getdecbit (hstr)
 
 dim result
 dim r(16)
 dim i
 
 result = 0
 
 r(0) = "0"
 r(1) = "1"
 r(2) = "2"
 r(3) = "3"
 r(4) = "4"
 r(5) = "5"
 r(6) = "6"
 r(7) = "7"
 r(8) = "8"
 r(9) = "9"
 r(10) = "a"
 r(11) = "b"
 r(12) = "c"
 r(13) = "d"
 r(14) = "e"
 r(15) = "f"
 
 for i = 0 to 15
  
  if hstr=r(i) then result = i : exit for
  
 next
 
 getdecbit = result
 
end function

%>