怎样用JavaScript实现验证码的验证

JavaScript019

怎样用JavaScript实现验证码的验证,第1张

用JavaScript实现验证码的验证主要代码如下:

var code //在全局定义验证码

//产生验证码

window.onload = function createCode(){

code = ""

var codeLength = 4//验证码的长度

var checkCode = document.getElementById("code")

var random = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R',

'S','T','U','V','W','X','Y','Z')//随机数

for(var i = 0i <codeLengthi++) {//循环操作

var index = Math.floor(Math.random()*36)//取得随机数的索引(0~35)

code += random[index]//根据索引取得随机数加到code上

}

checkCode.value = code//把code值赋给验证码

}

//校验验证码

function validate(){

var inputCode = document.getElementById("input").value.toUpperCase()//取得输入的验证码并转化为大写

if(inputCode.length <= 0) { //若输入的验证码长度为0

alert("请输入验证码!")//则弹出请输入验证码

}

else if(inputCode != code ) { //若输入的验证码与产生的验证码不一致时

alert("验证码输入错误!@_@")//则弹出验证码输入错误

createCode()//刷新验证码

document.getElementById("input").value = ""//清空文本框

}

else { //输入正确时

alert("^-^")//弹出^-^

}

}

最简单的方法你把图一的显示验证码也弄成一个图片,比如叫code.png,上面你的代码就能换成

<img src="code.png" onclick="this.src ={$maccms.path_tpl}picture/captcha.png"

<html>

<head>

<script language="javascript" type="text/javascript">

var code

function createCode(){

code = new Array()

var codeLength = 4

var checkCode = document.getElementById("checkCode")

checkCode.value = ""

var selectChar = new Array(2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','J','K','L','M','N','P','Q','R','S','T','U','V','W','X','Y','Z')

for(var i=0i<codeLengthi++) {

var charIndex = Math.floor(Math.random()*32)

code +=selectChar[charIndex]

}

checkCode.value = code

}

function validate () {

var inputCode = document.getElementById("yzm").value.toUpperCase()

if(inputCode != code ){

alert("验证码错误!")

return false

}

else {

alert("验证码正确!")

return true

}

}

</script>

<meta http-equiv="Content-Type" content="text/htmlcharset=gb2312">

</head>

<body onLoad="createCode()">

验证码:<input type="text" id="yzm" size="5" />

<input type="button" id="checkCode" onClick="createCode()" title="刷新验证码" style="width:50pxcolor:#F00border:0letter-spacing:1pxfont-family:Arial" />

<input type="button" id="Button1" onClick="validate()" value="确定" />

</body>

</html>