這篇文章主要介紹了vue+node實現圖片上傳及預覽的示例方法,小編覺得挺不錯的,現在分享給大家,也給大家做個參考。一起跟隨小編過來看看吧
本文介紹了vue+node實現圖片上傳及預覽的示例方法,分享給大家,具體如下:
先上效果圖
上代碼
html部分主要是藉助了weui的樣式
<template> <div> <myheader :title="'發佈動態'"> <i class="iconfont icon-fanhui1 left" slot="left" @click="goback"></i> </myheader> <div class="upload"> <div v-if="userInfo._id"> <!--圖片上傳--> <div class="weui-gallery" id="gallery"> <span class="weui-gallery__img" id="galleryImg"></span> <div class="weui-gallery__opr"> <a href="javascript:" rel="external nofollow" class="weui-gallery__del"> <i class="weui-icon-delete weui-icon_gallery-delete"></i> </a> </div> </div> <div class="weui-cells weui-cells_form"> <div class="weui-cell"> <div class="weui-cell__bd"> <textarea class="weui-textarea" v-model="content" placeholder="你想說啥" rows="3"></textarea> </div> </div> <div class="weui-cell"> <div class="weui-cell__bd"> <div class="weui-uploader"> <div class="weui-uploader__bd"> <ul class="weui-uploader__files" id="uploaderFiles"> <li ref="files" class="weui-uploader__file" v-for="(image,index) in images" :key="index" :style="'backgroundImage:url(' + image +' )'"><span @click="deleteimg(index)" class="x">×</span></li> </ul> <div v-show="images.length < maxCount" class="weui-uploader__input-box"> <input @change="change" id="uploaderInput" class="weui-uploader__input " type="file" multiple accept="image/*"> </div> </div> </div> </div> </div> </div> <a class="weui-btn weui-btn_primary btn-put" style="margin: 20px " @click.prevent.once="put">發送</a> </div> <unlogin v-else> </unlogin> </div> </div> </template>
重點部分在於
<ul class="weui-uploader__files" id="uploaderFiles"> <li ref="files" class="weui-uploader__file" v-for="(image,index) in images" :key="index" :style="'backgroundImage:url(' + image +' )'"><span @click="deleteimg(index)" class="x">×</span></li> </ul> <div v-show="!this.$refs.files||this.$refs.files.length < maxCount" class="weui-uploader__input-box"> <input @change="change" id="uploaderInput" class="weui-uploader__input" type="file" multiple accept="image/*"> </div>
通過@change="change"監聽圖片的上傳,把圖片轉成base64後(後面會講怎麼轉base64)將base64的地址加入到images數組,通過v-for="(image,index) in images"把要上傳的圖片在頁面中顯示出來,即達到了預覽的效果
js部分
data部分
data() { return { content: '',//分享動態的文字內容 maxSize: 10240000 / 2,//圖片的最大大小 maxCount: 8,//最大數量 filesArr: [],//保存要上傳圖片的數組 images: []//轉成base64後的圖片的數組 } }
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; // 如果沒有選中文件,直接返回 if (files.length === 0) { return; } if (this.images.length + files.length > this.maxCount) { Toast('最多隻能上傳' + this.maxCount + '張圖片!'); 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('圖片太大,不允許上傳!'); 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; // 設置 canvas 的寬度和高度 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中保存的圖片通過axios發送到後端,注意要設置headers信息
put() { Indicator.open('發佈中...'); 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.$router.push({path: '/home'}); Indicator.close(); Toast(result.data.msg) }) }
後端通過multer模塊保存傳輸的圖片,再把保存下來的圖片發送到阿里雲oss(這個可以根據自己的使用情況變化)
let filePath; let fileName; let Storage = multer.diskStorage({ destination: function (req, file, cb) {//計算圖片存放地址 cb(null, './public/img'); }, filename: function (req, file, cb) {//圖片文件名 fileName = Date.now() + '_' + parseInt(Math.random() * 1000000) + '.png'; filePath = './public/img/' + fileName; cb(null, fileName) } }); let upload = multer({storage: Storage}).any();//file2表示圖片上傳文件的key router.post('/uploadFile', function (req, res, next) { upload(req, res, function (err) { let content = req.body.content || ''; let username = req.body.username; let imgs = [];//要保存到數據庫的圖片地址數組 if (err) { return res.end(err); } if (req.files.length === 0) { new Pyq({ writer: username, content: content }).save().then((result) => { res.json({ result: result, code: '0', msg: '上傳成功' }); }) } /*client.delete('public/img/1.png', function (err) { console.log(err) });*/ let i = 0; req.files.forEach((item, index) => { let filePath = `./public/img/${item.filename}`; put(item.filename,filePath,(result)=>{ imgs.push(result.url); i++; if (i === req.files.length) { //forEach循環是同步的,但上傳圖片是異步的,所以用一個i去標記圖片是否全部上傳成功 //這時才把數據保存到數據庫 new Pyq({ content: content, writer: username, pimg: imgs }).save().then(() => { res.json({ code: '0', msg: '發佈成功' }); }) } }) }) }) });
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持神馬文庫。