js生成验证码并验证

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mob604756eb4476 2015-10-20 14:41:00

文章标签 验证码 html 随机数 javascript i++ 文章分类 代码人生

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>JS生成验证码</title>
<style type="text/css">
.code {
background-image: url(code.jpg);
font-family: Arial;
font-style: italic;
color: Red;
border: 0;
padding: 2px 3px;
letter-spacing: 3px;
font-weight: bolder;
}
.unchanged {
border: 0;
}
</style>
<script language="javascript" type="text/javascript">  
var code; //在全局 定义验证码   
function createCode() {
    code = "";
    var codeLength = 6;//验证码的长度   
    var checkCode = document.getElementById("checkCode");
    var selectChar = 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');//所有候选组成验证码的字符，当然也可以用中文的   

    for (var i = 0; i < codeLength; i++) {
        var charIndex = Math.floor(Math.random() * 36);
        code += selectChar[charIndex];
    }
    //alert(code);
    if (checkCode) {
        checkCode.className = "code";
        checkCode.value = code;
    }
}

function validate() {
    var inputCode = document.getElementById("input1").value;
    if (inputCode.length <= 0) {
        alert("请输入验证码！");
    } else if (inputCode != code) {
        alert("验证码输入错误！");
    createCode();//刷新验证码   
    } else {
    alert("^-^ OK");
    }
}
</script>
</head>
<body onload="createCode()">
<form action="#">
    <input type="text" id="input1" /> <input type="text" onclick="createCode()" readonly="readonly" id="checkCode" class="unchanged" style="width: 80px" /><br />
    <input id="Button1" onclick="validate();" type="button" value="确定" />
</form>
</body>
</html>

　　示例2：(推荐！)

HTML部分

<html>
  <head>
    <title>验证码</title>
    <style type="text/css">
      #code
      {
        font-family:Arial;
        font-style:italic;
        font-weight:bold;
        border:0;
        letter-spacing:2px;
        color:blue;　　　　　　　　　　　　　　　　　　 
                                width:60px;　　　　　　　　　　　　　　　　　　 
                                height:24px;
      }
    </style>
    <script type = "text/javascript" src = "checkCode.js">
    </script>
  </head>
  <body onload="createCode()">
    <div>
      <input type = "text" id = "input"/>
      <input type = "button" id="code" onclick="createCode()"/>
      <input type = "button" value = "验证" onclick = "validate()"/>
    </div>
  </body>
</html>

JS部分：checkCode.js

//在全局定义验证码 
　　　　　　var code ;

//产生验证码
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 = 0; i < codeLength; i++) {//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^-^
  }           
}