vue插件开发之使用pdf.js实现手机端在线预览pdf文档的方法

<template><p id="container">
  <!-- <p class='pdf-page'> -->
   <canvas id="the-canvas"></canvas></p><p class="foot" v-if="pdfDoc"><button class="left" click="onPrevPage" v-if="pageNum>1">上一页</button><button class="right" click="onNextPage" v-if="pageNum<pdfDoc.numPages">下一页</button></p>
  <!-- </p> --><p></p>
</template>
<script>
import PDFJS from 'pdfjs-dist'
 
export default {
 data () {
  return {
   pdfDoc: null,
   pageNum: 1,
   pageRendering: false,
   pageNumPending: null,
   scale: 0.9
  }
 },
 methods: {
  showPDF (url) {
   let _this = this
   PDFJS.getDocument(url).then(function (pdf) {
    _this.pdfDoc = pdf
    _this.renderPage(1)
   })
  },
  renderPage (num) {
   this.pageRendering = true
   let _this = this
   this.pdfDoc.getPage(num).then(function (page) {
    var viewport = page.getViewport(_this.scale)
    let canvas = document.getElementById('the-canvas')
    canvas.height = viewport.height
    canvas.width = viewport.width
 
    // Render PDF page into canvas context
    var renderContext = {
     canvasContext: canvas.getContext('2d'),
     viewport: viewport
    }
    var renderTask = page.render(renderContext)
 
    // Wait for rendering to finish
    renderTask.promise.then(function () {
     _this.pageRendering = false
     if (_this.pageNumPending !== null) {
      // New page rendering is pending
      this.renderPage(_this.pageNumPending)
      _this.pageNumPending = null
     }
    })
   })
  },
  queueRenderPage (num) {
   if (this.pageRendering) {
    this.pageNumPending = num
   } else {
    this.renderPage(num)
   }
  },
  onPrevPage () {
   if (this.pageNum <= 1) {
    return
   }
   this.pageNum--
   this.queueRenderPage(this.pageNum)
  },
  onNextPage () {
   if (this.pageNum >= this.pdfDoc.numPages) {
    return
   }
   this.pageNum++
   this.queueRenderPage(this.pageNum)
  }
 }
}
</script><style scoped="" type="text/css">#container {
 background-color: rgba(0,0,0,0.75);
 position:fixed;
 width: 100%;
 height: 100%;
 top: 0;
 left: 0;
 text-align: center;
 padding: 5px;
}
 
.pdf-page {
 
}
 
.foot {
 position: fixed;
 transform: translate(-50%,0);
 left: 50%;
}</style>

import PDF from './PDF'
 
var $vm
export default {
 install (Vue, options) {
  if (!$vm) {
   const PDFPlugin = Vue.extend(PDF)
   $vm = new PDFPlugin().$mount()
   document.body.appendChild($vm.$el)
  }
  Vue.prototype.$showPDF = function (url) {
   $vm.showPDF(url)
  }
 }
}

import pdf from '@/components/pdf'
Vue.use(pdf)

// ...
proxyTable: {
 '/media': {
  target: 'https://xxxx.cn', // 换成正确的服务器域名
  changeOrigin: true,
  pathRewrite: {
   '^/media': '/media'
  }
 }
}
// ...

// ...
mounted () {
 this.$showPDF('/media/up/2018/3/9/494079c7ec333bd371798dd0a73c0a0b.pdf')
}
// ...