一个注册框 进行表单验证处理
如图
有简单的验证提示功能
代码思路也比较简单
输入框失去焦点时便检测，并进行处理
表单具有 onsubmit = "return check()"行为，处理验证情况
点击提交表单按钮时，进行最终的验证，达到是否通过表单提交的请求。
先是最基本的html+css部分
<style type="text/css"> body{margin:0;padding: 0;} .login{position:relative;margin:100px auto;padding:50px 20px;width: 350px;height: 200px;border:1px solid #333;} .login legend{font-weight: bold;color: green;text-align: center;} .login label{display:inline-block;width:130px;text-align: right;} .btn{height: 30px;width:100px;padding: 5px;border:0;background-color: #00dddd;font-weight: bold;cursor: pointer;float: right;} input{height: 20px;width: 170px;} .borderRed{border: 2px solid red;} img{display: none;} </style> </head> <body> <div> <form method="post" action="register.php" onsubmit="return check()"> <legend>【Register】</legend> <p><label for="name">UserName: </label> <input type="text" > <img src="https://www.jb51.net/article/img/gou.png"></p> <p><label for="password">Password: </label> <input type="password" > <img src="https://www.jb51.net/article/img/gantan.png"></p> <p><label for="R_password">Password Again: </label> <input type="password" > <img src="https://www.jb51.net/article/img/gou.png"></p> <p><label for="email">Email: </label> <input type="text" > <img src="https://www.jb51.net/article/img/gou.png"></p> <p><input type="submit" value="Register"></p> </form> </div>
然后是js的class相关处理函数
function hasClass(obj,cls){ // 判断obj是否有此class return obj.className.match(new RegExp('(\\s|^)' + cls + '(\\s|$)')); } function addClass(obj,cls){ //给 obj添加class if(!this.hasClass(obj,cls)){ obj.className += " "+cls; } } function removeClass(obj,cls){ //移除obj对应的class if(hasClass(obj,cls)){ var reg = new RegExp('(\\s|^)' + cls + '(\\s|$)'); obj.className = obj.className.replace(reg," "); } }
然后是验证各个输入框的值
function checkName(name){ //验证name if(name != ""){ //不为空则正确，当然也可以ajax异步获取服务器判断用户名不重复则正确 removeClass(ele.name,"borderRed"); //移除class document.images[0].setAttribute("src","https://www.jb51.net/article/img/gou.png"); //对应图标 document.images[0].style.display = "inline"; //显示 return true; }else{ //name不符合 addClass(ele.name,"borderRed"); //添加class document.images[0].setAttribute("src","https://www.jb51.net/article/img/gantan.png"); //对应图标 document.images[0].style.display = "inline"; //显示 return false; } } function checkPassw(passw1,passw2){ //验证密码 if(passw1 == "" || passw2 == "" || passw1 !== passw2){ //两次密码输入不为空且不等 不符合 addClass(ele.password,"borderRed"); addClass(ele.R_password,"borderRed"); document.images[1].setAttribute("src","https://www.jb51.net/article/img/gantan.png"); document.images[1].style.display = "inline"; document.images[2].setAttribute("src","https://www.jb51.net/article/img/gantan.png"); document.images[2].style.display = "inline"; return false; }else{ //密码输入正确 removeClass(ele.password,"borderRed"); removeClass(ele.R_password,"borderRed"); document.images[1].setAttribute("src","https://www.jb51.net/article/img/gou.png"); document.images[1].style.display = "inline"; document.images[2].setAttribute("src","https://www.jb51.net/article/img/gou.png"); document.images[2].style.display = "inline"; return true; } } function checkEmail(email){ //验证邮箱 var pattern = /^([\.a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(\.[a-zA-Z0-9_-])+/; if(!pattern.test(email)){ //email格式不正确 addClass(ele.email,"borderRed"); document.images[3].setAttribute("src","https://www.jb51.net/article/img/gantan.png"); document.images[3].style.display = "inline"; ele.email.select(); return false; }else{ //格式正确 removeClass(ele.email,"borderRed"); document.images[3].setAttribute("src","https://www.jb51.net/article/img/gou.png"); document.images[3].style.display = "inline"; return true; } }
然后为各个输入框添加监听事件：
var ele = { //存放各个input字段obj name: document.getElementById("name"), password: document.getElementById("password"), R_password: document.getElementById("R_password"), email: document.getElementById("email") }; ele.name.onblur = function(){ //name失去焦点则检测 checkName(ele.name.value); } ele.password.onblur = function(){ //password失去焦点则检测 checkPassw(ele.password.value,ele.R_password.value); } ele.R_password.onblur = function(){ //R_password失去焦点则检测 checkPassw(ele.password.value,ele.R_password.value); } ele.email.onblur = function(){ //email失去焦点则检测 checkEmail(ele.email.value); }
最后就是点击提交注册时调用的check()函数了