vue实现验证码按钮倒计时功能

2019-11-19 14:02:18

字体：大中小

来源：转载

供稿：网友

本人最近开始尝试学习vue.js。想使用vue写一个小例子，就选择做验证码按钮倒计时功能。

上网上搜了一下，也把他们的代码试了一下，自己出了很多问题。所以，需要写一篇基础入门的文章，避免后面人采坑。

这是按照网上写的HTML页面

<div class="register-pannel" id ="register-pannel">       <div class="register-l" align="center">         <div class="input-group" style="width: 300px;">           <input type="text" class="form-control" placeholder="邮箱/手机号/用户名" style="height: 40px;" />           <span class="glyphicon glyphicon-user form-control-feedback" aria-hidden="true" />         </div>         <br />         <div class="input-group" style="width: 300px;">           <input type="text" class="form-control" placeholder="密码" style="height: 40px;" />           <span class="glyphicon glyphicon-lock form-control-feedback" />         </div>         <br />         <div class="input-group" style="width: 300px;">           <input type="text" class="form-control" placeholder="手机号" style="height: 40px;" />           <span class="glyphicon glyphicon-phone form-control-feedback" />         </div>         <br />         <div class="input-group" style="width: 300px;">             <span class="register-msg-btn" v-show="show" v-on:click="getCode">发送验证码</span>             <span class="register-msg-btn" v-show="!show">{{count}} s</span>           <input type="text" class="form-control" placeholder="验证码" style="float: right; height: 40px; width: 150px;" />           <span class="glyphicon glyphicon-font form-control-feedback" />         </div>         <br />         <span class="btn-register">注册</span>       </div>

js写成

<script> <span style="white-space: pre;">      </span>data(){   <span style="white-space: pre;">      </span>return {   <span style="white-space: pre;">        </span>show: true,   <span style="white-space: pre;">        </span>count: '',   <span style="white-space: pre;">        </span>timer: null,   <span style="white-space: pre;">      </span>}  <span style="white-space: pre;">    </span>},  <span style="white-space: pre;">    </span>methods:{   <span style="white-space: pre;">      </span>getCode(){    <span style="white-space: pre;">        </span>const TIME_COUNT = 60;    <span style="white-space: pre;">        </span>if (!this.timer) {     <span style="white-space: pre;">          </span>this.count = TIME_COUNT;     <span style="white-space: pre;">          </span>this.show = false;     <span style="white-space: pre;">          </span>this.timer = setInterval(() => {     <span style="white-space: pre;">            </span>if (this.count > 0 && this.count <= TIME_COUNT) {      <span style="white-space: pre;">              </span>this.count--;      <span style="white-space: pre;">            </span>} else {      <span style="white-space: pre;">              </span>this.show = true;      <span style="white-space: pre;">              </span>clearInterval(this.timer);      <span style="white-space: pre;">              </span>this.timer = null;      <span style="white-space: pre;">            </span>}     <span style="white-space: pre;">          </span>}, 1000)     <span style="white-space: pre;">        </span>}   <span style="white-space: pre;">      </span>}   <span style="white-space: pre;">    </span>} </script>

发现浏览器一直报错Uncaught SyntaxError: Unexpected token {

所以按照官方文档的格式，把js的结构改成

<script>     new Vue({       el:'.register-pannel',            data:{            show:true,           timer:null,         count:''       },        methods:{           getCode(){           this.show = false;           const TIME_COUNT = 60;              if (!this.timer) {                 this.count = TIME_COUNT;                 this.show = false;                 this.timer = setInterval(() => {                   if (this.count > 0 && this.count <= TIME_COUNT) {                      this.count--;                    } else {                      this.show = true;                      clearInterval(this.timer);                      this.timer = null;                    }                 }, 1000)               }           }         }     });     </script>

于是格式是没有问题了，但是样式并没有生效。变成了另一个样子。

上网上搜了很多。

有说是js引用顺序的问题。

有说是将js写进window.onload的。试了一下，发现都不对。

后来，在官方文档中发现了el属性：为实例提供挂载元素。值可以是 CSS 选择符，或实际 HTML 元素，或返回 HTML 元素的函数。

所以改成

<script> new Vue({  el:'.register-pannel', //注册div的class   data:{     show:true,    timer:null,  count:''  },   methods:{    getCode(){   this.show = false;   const TIME_COUNT = 60;      if (!this.timer) {       this.count = TIME_COUNT;       this.show = false;       this.timer = setInterval(() => {        if (this.count > 0 && this.count <= TIME_COUNT) {         this.count--;         } else {         this.show = true;         clearInterval(this.timer);         this.timer = null;         }       }, 1000)       }    }    } });</script>

效果就出来了。