上代码
html部分主要是借助了weui的样式
<template> <div> <myheader :title="'发布动态'"> <i slot="left" @click="goback"></i> </myheader> <div> <div v-if="userInfo._id"> <!--图片上传--> <div> <span></span> <div> <a href="javascript:"> <i></i> </a> </div> </div> <div> <div> <div> <textarea v-model="content" placeholder="你想说啥" rows="3"></textarea> </div> </div> <div> <div> <div> <div> <ul> <li ref="files" v-for="(image,index) in images" :key="index" :style="'backgroundImage:url(' + image +' )'"><span @click="deleteimg(index)">×</span></li> </ul> <div v-show="images.length < maxCount"> <input @change="change" type="file" multiple accept="image/*"> </div> </div> </div> </div> </div> </div> <a @click.prevent.once="put">发送</a> </div> <unlogin v-else> </unlogin> </div> </div> </template>
重点部分在于
<ul> <li ref="files" v-for="(image,index) in images" :key="index" :style="'backgroundImage:url(' + image +' )'"><span @click="deleteimg(index)">×</span></li> </ul> <div v-show="!this.$refs.files||this.$refs.files.length < maxCount"> <input @change="change" type="file" multiple accept="image/*"> </div>
通过@change="change"监听图片的上传，把图片转成base64后（后面会讲怎么转base64）将base64的地址加入到images数组，通过v-for="(image,index) in images"把要上传的图片在页面中显示出来，即达到了预览的效果
js部分
data部分
data() { return { content: '',//分享动态的文字内容 maxSize: 10240000 / 2,//图片的最大大小 maxCount: 8,//最大数量 filesArr: [],//保存要上传图片的数组 images: []//转成base64后的图片的数组 } }
delete方法
deleteimg(index) { this.filesArr.splice(index, 1); this.images.splice(index, 1); }
change方法
change(e) { let files = e.target.files; // 如果没有选中文件，直接返回 if (files.length === 0) { return; } if (this.images.length + files.length > this.maxCount) { Toast('最多只能上传' + this.maxCount + '张图片！'); return; } let reader; let file; let images = this.images; for (let i = 0; i < files.length; i++) { file = files[i]; this.filesArr.push(file); reader = new FileReader(); if (file.size > self.maxSize) { Toast('图片太大，不允许上传！'); continue; } reader.onload = (e) => { let img = new Image(); img.onload = function () { let canvas = document.createElement('canvas'); let ctx = canvas.getContext('2d'); let w = img.width; let h = img.height; // 设置 canvas 的宽度和高度 canvas.width = w; canvas.height = h; ctx.drawImage(img, 0, 0, w, h); let base64 = canvas.toDataURL('image/png'); images.push(base64); }; img.src = e.target.result; }; reader.readAsDataURL(file); } }
put方法把filesArr中保存的图片通过axios发送到后端,注意要设置headers信息
put() { Indicator.open('发布中...'); let self = this; let content = this.content; let param = new FormData(); param.append('content', content); param.append('username', this.userInfo._id); this.filesArr.forEach((file) => { param.append('file2', file); }); self.axios.post('/upload/uploadFile', param, { headers: { "Content-Type": "application/x-www-form-urlencoded" } }).then(function (result) { console.log(result.data); self.$router.push({path: '/home'}); Indicator.close(); Toast(result.data.msg) }) }
后端通过multer模块保存传输的图片，再把保存下来的图片发送到阿里云oss（这个可以根据自己的使用情况变化）
let filePath; let fileName; let Storage = multer.diskStorage({ destination: function (req, file, cb) {//计算图片存放地址 cb(null, './public/img'); }, filename: function (req, file, cb) {//图片文件名 fileName = Date.now() + '_' + parseInt(Math.random() * 1000000) + '.png'; filePath = './public/img/' + fileName; cb(null, fileName) } }); let upload = multer({storage: Storage}).any();//file2表示图片上传文件的key router.post('/uploadFile', function (req, res, next) { upload(req, res, function (err) { let content = req.body.content || ''; let username = req.body.username; let imgs = [];//要保存到数据库的图片地址数组 if (err) { return res.end(err); } if (req.files.length === 0) { new Pyq({ writer: username, content: content }).save().then((result) => { res.json({ result: result, code: '0', msg: '上传成功' }); }) } /*client.delete('public/img/1.png', function (err) { console.log(err) });*/ let i = 0; req.files.forEach((item, index) => { let filePath = `./public/img/${item.filename}`; put(item.filename,filePath,(result)=>{ imgs.push(result.url); i++; if (i === req.files.length) { //forEach循环是同步的，但上传图片是异步的，所以用一个i去标记图片是否全部上传成功 //这时才把数据保存到数据库 new Pyq({ content: content, writer: username, pimg: imgs }).save().then(() => { res.json({ code: '0', msg: '发布成功' }); }) } }) }) }) });