验证码的作用：
1.有效防止这种问题对某一个特定注册用户用特定程序暴力破解方式进行不断的登陆尝试，实际上是用验证码是现在很多网站通行的方式（比如招商银行的网上个人银行，腾讯的QQ社区），我们利用比较简易的方式实现了这个功能。
2.防止批量注册
首先要准备jquery、jquery.idcode.css 和 jquery.idcode.js 三个脚本,然后再html文档中进行实例生成。
jquery.idcode.css 样式:
1 @charset "utf-8"; 2 /* track base Css */ 3 4 .ehong-idcode-val{ 5 position:relative; 6 padding:1px 4px 1px 4px; 7 top:0px; 8 *top:-3px; 9 letter-spacing:4px; 10 display:inline; 11 cursor:pointer; 12 font-size:20px; 13 font-family:"Courier New", Courier, monospace; 14 text-decoration:none; 15 font-weight:bold; 16 } 17 .ehong-idcode-val0{ 18 border:solid 1px #A4CDED; 19 background-color:#ECFAFB; 20 } 21 22 .ehong-idcode-val1{ 23 border:solid 1px #A4CDED; 24 background-color:#FCEFCF; 25 } 26 .ehong-idcode-val2{ 27 border:solid 1px #6C9; 28 background-color:#D0F0DF; 29 } 30 .ehong-idcode-val3{ 31 border:solid 1px #6C9; 32 background-color:#DCDDD8; 33 } 34 .ehong-idcode-val4{ 35 border:solid 1px #6C9; 36 background-color:#F1DEFF; 37 } 38 .ehong-idcode-val5{ 39 border:solid 1px #6C9; 40 background-color:#ACE1F1; 41 } 42 .ehong-code-val-tip{ 43 font-size:12px; 44 color:#1098EC; 45 top:0px; 46 *top:-3px; 47 position:relative; 48 margin:0px 0px 0px 4px; 49 cursor:pointer; 50 }
jquery.idcode.js 脚本:
1 (function($){ 2 var settings = { 3 e : 'idcode', 4 codeType : { name : 'follow', len: 4}, 5 codeTip : 'refresh?', 6 inputID : 'Txtidcode' //引用验证码输入框Id 7 }; 8 9 var _set = { 10 storeLable : 'codeval', 11 store : '#ehong-code-input', 12 codeval : '#ehong-code' 13 } 14 $.idcode = { 15 getCode:function(option){ 16 _commSetting(option); 17 return _storeData(_set.storeLable, null); 18 }, 19 setCode:function(option){ 20 _commSetting(option); 21 _setCodeStyle("#"+settings.e, settings.codeType.name, settings.codeType.len); 22 23 }, 24 validateCode:function(option){ 25 _commSetting(option); 26 var inputV; 27 if(settings.inputID){ 28 inputV=$('#' + settings.inputID).val(); 29 }else{ 30 inputV=$(_set.store).val(); 31 } 32 33 if(inputV == _storeData(_set.storeLable, null)){ 34 return true; 35 }else{ 36 _setCodeStyle("#"+settings.e, settings.codeType.name, settings.codeType.len); 37 return false; 38 } 39 } 40 }; 41 42 function _commSetting(option){ 43 $.extend(settings, option); 44 } 45 46 function _storeData(dataLabel, data){ 47 var store = $(_set.codeval).get(0); 48 if(data){ 49 $.data(store, dataLabel, data); 50 }else{ 51 return $.data(store, dataLabel); 52 } 53 } 54 55 function _setCodeStyle(eid, codeType, codeLength){ 56 var codeObj = _createCode(settings.codeType.name, settings.codeType.len); 57 var randNum = Math.floor(Math.random()*6); 58 var htmlCode='' 59 if(!settings.inputID){ 60 htmlCode='<span><input id="ehong-code-input" type="text" maxlength="4" /></span>'; 61 } 62 htmlCode+='<div id="ehong-code" class="ehong-idcode-val ehong-idcode-val'; 63 htmlCode+=String(randNum); 64 htmlCode+='" href="#" onblur="return false" onfocus="return false" oncontextmenu="return false" onclick="$.idcode.setCode()">' + _setStyle(codeObj) + '</div>' + '<span id="ehong-code-tip-ck" class="ehong-code-val-tip" onclick="$.idcode.setCode()">'/*+ settings.codeTip*/ +'</span>'; 65 $(eid).html(htmlCode); 66 _storeData(_set.storeLable, codeObj); 67 } 68 69 function _setStyle(codeObj){ 70 var fnCodeObj = new Array(); 71 var col = new Array('#BF0C43', '#E69A2A','#707F02','#18975F','#BC3087','#73C841','#780320','#90719B','#1F72D8','#D6A03C','#6B486E','#243F5F','#16BDB5'); 72 var charIndex; 73 for(var i=0;i<codeObj.length;i++){ 74 charIndex = Math.floor(Math.random()*col.length); 75 fnCodeObj.push('<font color="' + col[charIndex] + '">' + codeObj.charAt(i) + '</font>'); 76 } 77 return fnCodeObj.join(''); 78 } 79 function _createCode(codeType, codeLength){ 80 var codeObj; 81 if(codeType=='follow'){ 82 codeObj = _createCodeFollow(codeLength); 83 }else if(codeType=='calc'){ 84 codeObj = _createCodeCalc(codeLength); 85 }else{ 86 codeObj=""; 87 } 88 return codeObj; 89 } 90 91 function _createCodeCalc(codeLength){ 92 var code1, code2, codeResult; 93 var selectChar = new Array('0','1','2','3','4','5','6','7','8','9'); 94 var charIndex; 95 for(var i=0;i<codeLength;i++){ 96 charIndex = Math.floor(Math.random()*selectChar.length); 97 code1 +=selectChar[charIndex]; 98 99 charIndex = Math.floor(Math.random()*selectChar.length); 100 code2 +=selectChar[charIndex]; 101 } 102 return [parseInt(code1), parseInt(code2) , parseInt(code1) + parseInt(code2)] ; 103 } 104 105 function _createCodeFollow(codeLength){ 106 var code = ""; 107 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'); 108 109 for(var i=0;i<codeLength;i++){ 110 var charIndex = Math.floor(Math.random()*selectChar.length); 111 if(charIndex % 2 == 0){ 112 code+=selectChar[charIndex].toLowerCase(); 113 }else{ 114 code +=selectChar[charIndex]; 115 } 116 } 117 return code; 118 } 119 120 })(jQuery);
jquery 的脚本从官网上下载即可。
html代码部分:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>jQuery区分大小写验证码</title> <!--//引用css--> <link href="css/jquery.idcode.css" type="text/css" rel="stylesheet"> </head> <body> <center><br><br> <input type="text" id ="Txtidcode" class ="txtVerification"><span id="idcode"></span> <input type="button" id="butn" value="提交"></center> <script src="js/jquery-1.12.3.min.js"></script> <!--//引用idcode插件--> <script src="js/jquery.idcode.js"></script> <script> $.idcode.setCode(); //加载生成验证码方法 $("#butn").click(function(){ var IsBy = $.idcode.validateCode() //调用返回值，返回值结果为true或者false if(IsBy){ alert("验证码输入正确") }else { alert("请重新输入") } }) </script> </body> </html>