htmlToPdf

1. import htmlToPdf from './utils/htmlToPdf.js'
   Vue.use(htmlToPdf)
   // htmlToPdf.js
   // 导出页面为PDF格式
   /* 
    用法
   
   1. main.js中引入
      import htmlToPdf from '@/util/htmlToPdf'
      Vue.use(htmlToPdf)
   
   2. vue页面中调用
      按钮中方法  @click="getPdf()"
      data中声明变量 
      data() {
      return {
      	htmlTitle: "测试导出文件", // 生成pdf的名称 
      	......
   3. 打印内容 id必须为pdfDom
   import html2Canvas from 'html2canvas'
   import JsPDF from 'jspdf'
   export default {
   	install(Vue, options) {
   		Vue.prototype.getPdf = function() {
   			var title = this.htmlTitle //
   			html2Canvas(document.querySelector('#pdfDom'), {
   				allowTaint: true,
   				taintTest: false,
   				useCORS: true,
   				// y: 72, // 对Y轴进行裁切
   				// width:1200,
   				// height:5000,
   				dpi: window.devicePixelRatio * 4, //将分辨率提高到特定的DPI 提高四倍
   				scale: 4 //按比例增加分辨率 
   			}).then(function(canvas) {
   				let contentWidth = canvas.width
   				let contentHeight = canvas.height
   				let pageHeight = contentWidth / 592.28 * 841.89
   				let leftHeight = contentHeight
   				let position = 0
   				let imgWidth = 595.28
   				let imgHeight = 592.28 / contentWidth * contentHeight
   				let pageData = canvas.toDataURL('image/jpeg', 1.0)
   				let PDF = new JsPDF('', 'pt', 'a4')
   				if (leftHeight < pageHeight) {
   					PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
   				} else {
   					while (leftHeight > 0) {
   						PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
   						leftHeight -= pageHeight
   						position -= 841.89
   						if (leftHeight > 0) {
   							PDF.addPage()
   						}
   					}
   				}
   				PDF.save(title + '.pdf')
   			})
   		}
   	}
   }