- A+
所属分类：Web前端
第一步：先下载pdfjs，网址：PDF下载地址，再引入到项目中，我是标签直接引用的
<script src="pdfjs/build/pdf.js"></script> <script src="pdfjs/build/pdf.worker.js"></script>
第二步：html代码添加两行代码，一个是canvas用来绘图，一个是img用来最后展示转换后的pdf图片
<body> <img :src="imgUrl" alt="" width="100%" height="auto"> <canvas id="the-canvas" style="display: none"></canvas> </body>
第三步：js代码块，主要是将paf通过pdfjs插件绘制到canvas，然后再转换为base64格式的图片
//url参数是pdf地址，imgUrl是最后的base64格式图片 showPdf(url) { let _this = this; let imgArr = []; pdfjsLib.workerSrc = 'pdf.worker.js'; let loadingTask = pdfjsLib.getDocument(url); loadingTask.promise.then(function(pdf) { console.log('PDF loaded'); let pageNum = pdf.numPages; // console.log(pageNum); for (let i=1; i<=pageNum; i++) { pdf.getPage(i).then(function(page) { console.log('Page loaded'); let scale = 1; let viewport = page.getViewport(scale); // let canvas = document.getElementById('the-canvas'); let canvas = document.createElement("canvas"); let context = canvas.getContext('2d'); canvas.height = viewport.height; canvas.width = viewport.width; let renderContext = { canvasContext: context, viewport: viewport }; let renderTask = page.render(renderContext); renderTask.then(function () { console.log('Page rendered'); let imgUrl = canvas.toDataURL('image/jpeg'); //转换为base64 if (imgUrl) { imgArr[i-1] = imgUrl; } //pdf全部画完结束后操作 if (imgArr.length==pageNum&&!isEmpty(imgArr)) { // let canvas2 = document.createElement("canvas"); let canvas2 = document.getElementById('the-canvas'); let context2 = canvas2.getContext('2d'); canvas2.height = viewport.height*pageNum; canvas2.width = viewport.width; let count = 0; for (let j=0; j<imgArr.length; j++) { let IMG = new Image(); IMG.src=imgArr[j]; IMG.width = viewport.width; IMG.height = viewport.height; IMG.onload = function () { context2.drawImage(IMG,0,viewport.height*j); count++;//确保所有img渲染结束后操作 if (count==pageNum) { let canvas = document.getElementById('the-canvas'); //赋值给img _this.imgUrl = canvas.toDataURL('image/jpeg'); } } } } }); }); } }, function (reason) { console.error(reason); }); function isEmpty(arr) { for(let i=0;i<arr.length;i++) { if(!arr[i]) return true; } return false; } }
