asp经典验证码

2015/01/18 33426
asp验证码代码 (带刷新)
asp验证码代码 (带刷新) 
将以下代码放到一个单独的页面checkcode.asp 


<% 
Option Explicit 
Response.buffer=true 
Call Com_CreatValidCode("validateCode") 

Sub Com_CreatValidCode(pSN) 
' 禁止缓存 
Response.Expires = -9999 
Response.AddHeader "Pragma","no-cache" 
Response.AddHeader "cache-ctrol","no-cache" 
Response.ContentType = "Image/BMP" 

Randomize 

Dim i, ii, iii 

Const cOdds = 2 ' 杂点出现的机率 
Const cAmount = 10 ' 文字数量 
Const cCode = "0123456789" 

' 颜色的数据(字符，背景) 
Dim vColorData(1) 
vColorData(0) = ChrB(0) & ChrB(0) & ChrB(211) ' 蓝0，绿0，红0（黑色） 
vColorData(1) = ChrB(255) & ChrB(255) & ChrB(255) ' 蓝250，绿236，红211（浅蓝色） 

' 随机产生字符 
Dim vCode(4), vCodes 
For i = 0 To 3 
vCode(i) = Int(Rnd * cAmount) 
vCodes = vCodes & Mid(cCode, vCode(i) + 1, 1) 
Next 
Session(pSN) = vCodes '记录入Session 
' 字符的数据 
Dim vNumberData(9) 
vNumberData(0) = 

"1110000111110111101111011110111101001011110100101111010010111101001011110111101111011110111

110000111" 
vNumberData(1) = 

"1111011111110001111111110111111111011111111101111111110111111111011111111101111111110111111

100000111" 
vNumberData(2) = 

"1110000111110111101111011110111111111011111111011111111011111111011111111011111111011110111

100000011" 
vNumberData(3) = 

"1110000111110111101111011110111111110111111100111111111101111111111011110111101111011110111

110000111" 
vNumberData(4) = 

"1111101111111110111111110011111110101111110110111111011011111100000011111110111111111011111

111000011" 
vNumberData(5) = 

"1100000011110111111111011111111101000111110011101111111110111111111011110111101111011110111

110000111" 
vNumberData(6) = 

"1111000111111011101111011111111101111111110100011111001110111101111011110111101111011110111

110000111" 
vNumberData(7) = 

"1100000011110111011111011101111111101111111110111111110111111111011111111101111111110111111

111011111" 
vNumberData(8) = 

"1110000111110111101111011110111101111011111000011111101101111101111011110111101111011110111

110000111" 
vNumberData(9) = 

"1110001111110111011111011110111101111011110111001111100010111111111011111111101111011101111

110001111" 
' 输出图像文件头 
Response.BinaryWrite ChrB(66) & ChrB(77) & ChrB(230) & ChrB(4) & ChrB(0) & ChrB(0) & ChrB(0) 

& ChrB(0) &_ 
ChrB(0) & ChrB(0) & ChrB(54) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(40) & ChrB(0) &_ 
ChrB(0) & ChrB(0) & ChrB(40) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(10) & ChrB(0) &_ 
ChrB(0) & ChrB(0) & ChrB(1) & ChrB(0) 

' 输出图像信息头 
Response.BinaryWrite ChrB(24) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(176) 

& ChrB(4) &_ 
ChrB(0) & ChrB(0) & ChrB(18) & ChrB(11) & ChrB(0) & ChrB(0) & ChrB(18) & ChrB(11) &_ 
ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) &_ 
ChrB(0) & ChrB(0) 

For i = 9 To 0 Step -1 ' 历经所有行 
For ii = 0 To 3 ' 历经所有字 
For iii = 1 To 10 ' 历经所有像素 
' 逐行、逐字、逐像素地输出图像数据 
If Rnd * 99 + 1 < cOdds Then ' 随机生成杂点 
Response.BinaryWrite vColorData(0) 
Else 
Response.BinaryWrite vColorData(Mid(vNumberData(vCode(ii)), i * 10 + iii, 1)) 
End If 
Next 
Next 
Next 
End Sub 
%> 
需要用得页面用如下方式引用： 
验证码： <input name="txt_check" type="text" size=6 maxlength=4 class="input"> <img 

src="checkcode.asp " alt="验证码,看不清楚?请点击刷新验证码" height="10" style="cursor : 

pointer;" onClick="this.src='checkcode.asp?t='+(new Date().getTime());" > 

判断页面： 
<% 
if trim(session("validateCode")) <> trim(Request("txt_check")) then 
ErrorMessage = "请输入正确的验证码" 
response.write(" <script>alert('"&ErrorMessage&"');location.href='Default.asp' </script>") 
response.end 
end if 
%>
代码片段
