这里讲解是图片上传和图片预览。主要是围绕我们常用功能的列子做讲解 ,并且没有格外引入其他js 所以你复制过去做简单修改便可以看到效果

效果图：

样式以及效果图一并展示

1.HTML

<div class="rz-picter">
 <img :src="avatar" class="img-avatar">
 <input type="file" name="avatar" id="uppic" accept="image/gif,image/jpeg,image/jpg,image/png" @change="changeImage($event)" ref="avatarInput" class="uppic">
 </div>

2.js

data() {
 return {
 avatar: require('../assets/jia.jpg'),
 }
 },

图片一定要以require 的方式引入 这里的图片仅用来美化 并不是上传的图片

3.js 写方法

 changeImage(e) {
 var file = e.target.files[0]
 var reader = new FileReader()
 var that = this
 reader.readAsDataURL(file)
 reader.onload = function(e) {
 that.avatar = this.result
 }
 },

就这么几段代码一个上传功能就写好了

4.切记我这里用了css来将input  type = file 的样式重新优化了，并且将图片做了定位 所以点击中间图片就可以触发上传

你需要你的需求去定义你的样式

5.运用原生javascript我做了一个判断图片是否上传的的判断

if(document.getElementById('uppic').value.length == '') {
 Toast('请上传图片');
 return
 }

6.附上css代码

 .uppic {
 height: 3rem;
 width: 6rem;
 margin: 0 auto;
 opacity: 0;
 z-index: 99999;
 }
 .img-avatar {
 position: absolute;
 }

附上写此功能所有代码

<template>
 <div class="renzheng">
 <div class="rz-notice" v-bind:style="{ display: isno}">
 <p>名片用来鉴别是相关人员，温馨提示：<img src="../assets/static/img-icon/lan_cha.png" @click="hiddenwords"></p>
 </div>
 <van-tabs v-model="active" swipeable>
 <van-tab v-for="(item,index) in navArr" :title="item.name" class="v-tab">
 <div v-if="index==0">
 <div class="color-black" style="text-align: center;margin-top: 0.4rem;">请上传本人名片照片</div>
 <div class="rz-picter">
 <img :src="avatar" class="img-avatar">
 <input type="file" name="avatar" id="uppic" accept="image/gif,image/jpeg,image/jpg,image/png" @change="changeImage($event)" ref="avatarInput" class="uppic">
 </div>
 <div class="cuxian"></div>
 <div class="my-content-list">
 <div class="color-black"><span style="margin-right: 0.6rem;">真实姓名:</span><input v-model="yoursname" placeholder="请输入您的真实姓名" /></div>
 </div>
 <div class="my-content-list">
 <div class="color-black"><span style="margin-right: 0.6rem;">手机号码:</span><input type="number" max="11" v-model="yoursphone" placeholder="请输入您的手机号码" /></div>
 </div>
 <div class="yzbtn" @click="submitBtn">
 立即认证
 </div>
 </div>
 <div v-if="index==1">
 <div class="color-black" style="text-align: center;margin-top: 0.4rem;">请上传本人身份证照片</div>
 <div class="rz-picter">
 <img src="../assets/jia.jpg" />
 <p>上传人像页</p>
 </div>
 <div class="rz-picter">
 <img src="../assets/jia.jpg" />
 <p>上传国辉页</p>
 </div>
 <div class="cuxian"></div>
 <div class="my-content-list">
 <div class="color-black"><span style="margin-right: 0.6rem;">真实姓名:</span><input placeholder="请输入您的真实姓名" /></div>
 </div>
 <div class="my-content-list">
 <div class="color-black"><span style="margin-right: 0.6rem;">手机号码:</span><input type="number" placeholder="请输入您的手机号码" /></div>
 </div>
 <div class="yzbtn">
 立即认证
 </div>
 </div>
 </van-tab>
 </van-tabs>
 </div>
</template>
<script>
 import { Tab, Tabs } from 'vant';
 import { Toast } from 'vant'
 export default {
 name: 'renzheng',
 data() {
 return {
 yoursname: '',
 yoursphone: '',
 avatar: require('../assets/jia.jpg'),
 isno: 'block',
 active: 0,
 navArr: [{
 name: "身份认证"
 },
 {
 name: "实名认证"
 }
 ],
 }
 },
 methods: {
 hiddenwords() {
 this.isno = 'none'
 },
 submitBtn() {
 if(this.yoursname == '') {
 Toast("请填写你的真实姓名");
 return;
 }
 if(this.yoursphone == '' || this.yoursphone == null) {
 Toast("请填写你的手机号码");
 return;
 }
 if(document.getElementById('uppic').value.length == '') {
 Toast('请上传图片');
 return;
 }
 },
 changeImage(e) {
 var file = e.target.files[0]
 var reader = new FileReader()
 var that = this
 reader.readAsDataURL(file)
 reader.onload = function(e) {
 that.avatar = this.result
 }
 },
 },
 mounted: function() {
 }
 }
</script>
<style>
 .rz-notice {
 padding: 0.2rem 0.3rem;
 display: flex;
 flex-direction: row;
 justify-content: space-between;
 align-items: center;
 background: #F0F5FB;
 color: #28D9EF;
 }
 
 .rz-notice img {
 height: 0.22rem;
 width: 0.22rem;
 }
 
 .rz-picter {
 height: 3rem;
 width: 6rem;
 margin: 0.3rem auto;
 border: 0.01rem solid #ededed;
 display: flex;
 flex-direction: column;
 align-items: center;
 justify-content: center;
 }
 
 .uppic {
 height: 3rem;
 width: 6rem;
 margin: 0 auto;
 opacity: 0;
 z-index: 99999;
 }
 .img-avatar {
 position: absolute;
 }
 /*立即验证*/
 
 .yzbtn {
 width: 90%;
 height: 0.8rem;
 background: #FF6600;
 border-radius: 0.06rem;
 margin: 30px auto;
 text-align: center;
 line-height: 0.8rem;
 color: #FFFFFF
 }
 
 
 /*修改原有tab样式*/
 
 .van-tab {
 color: #A3A3A3!important;
 }
 
 .van-tab--active {
 color: #000!important;
 }
 
 .van-tabs__line {
 background-color: #FF6600!important;
 width: 0.7rem!important;
 text-align: center!important;
 align-items: center;
 margin-left: 1.5rem;
 }
 
 .van-toast {
 background-color: #FF6600;
 color: #FFFFFF
 }
 
 .my-content-list {
 padding: 0.3rem;
 display: flex;
 flex-direction: row;
 justify-content: space-between;
 border-bottom: 0.01rem solid #EDEDED;
 }
</style>

总结

以上所述是小编给大家介绍的vue.js 图片上传并预览及图片更换功能的实现代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！