分享给大家一段js生成验证码并验证的代码
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<!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 > |
众所周知,js是客户端的,那么把验证都做在客户端有意义吗?还是必须从服务器生成的验证码安全啊?前端生成的验证码安全吗?
验证码是动态的,但要由客户端识别,并返回正确数值才能正常验证。这是一个流程问题,如果js的,那就是在客户端处验证,基本等于没有一样!!!最好是服务器生成,客户端验证,服务器确认,正常浏览。这样一个流程就万无一失
所以,本文仅仅是技术探讨而已,千万别用在实际生产项目中