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  • 使用js实现登录随机验证码的效果

    <!DOCTYPE html>
    <html lang="en">
    <head>
    <meta charset="UTF-8">
    <title>js验证码</title>
    <style type="text/css">
    .code
    {
    background:url(code_bg.jpg);
    font-family:Arial;
    font-style:italic;
    color:blue;
    font-size:16px;
    border:0;
    padding:2px 3px;
    letter-spacing:3px;
    font-weight:bolder;
    float:left;
    cursor:pointer;
    150px;
    text-align:center;
    vertical-align:middle;
    }
    a
    {
    text-decoration:none;
    font-size:12px;
    color:#288bc4;
    }
    a:hover
    {
    text-decoration:underline;
    }
    </style>
    <script type="text/javascript">
    var code;
    function createCode()
    {
    code = "";
     
    var codeLength = 4;  //验证码的长度
    var checkCode = document.getElementById("checkCode");
    var codeChars = 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',
    '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 charNum = Math.floor(Math.random() * 52);
    code += codeChars[charNum];
    }
    if(checkCode)
    {
    checkCode.className = "code";
    checkCode.innerHTML = code;
    }
    }
    function validateCode()
    {
    var inputCode=document.getElementById("inputCode").value;
    if(inputCode.length <= 0)
    {
    alert("请输入验证码!");
    }
    else if(inputCode.toUpperCase() != code.toUpperCase())
    {
    alert("验证码输入有误!");
    createCode();
    }
    else
    {
    alert("验证码正确!");
    }
    }
    </script>
    </head>
    <body onload="createCode()">
    <form id="form1" runat="server" onsubmit="validateCode()">
    <div>
    <table border="0" cellspacing="5" cellpadding="5" >
    <tr>
    <td></td>
    <td><div class="code" id="checkCode" onclick="createCode()" style="border:1px solid #ccc; height:30px;line-height:30px;" ></div></td>
    <td><a href="#" onclick="createCode()">看不清换一张</a></td>
    </tr>
    <tr>
    <td>验证码:</td>
    <td><input style="float:left;" type="text" id="inputCode" /></td>
    <td>请输入验证码</td>
    </tr>
    <tr>
    <td></td>
    <td><input id="Button1" onclick="validateCode();" type="button" value="确定" /></td>
    <td></td>
    </tr>
    </table>
    </div>
    </form>


    </body>
    </html>

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  • 原文地址:https://www.cnblogs.com/jack-lin/p/6476882.html
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