1.下载插件模块

   npm install html2canvas jspdf --save

2.引入插件

	import html2canvas from 'html2canvas';
	import jspdf from 'jspdf';

3.功能实现方法

// 下载pdf
			downPdf() {

				window.scrollTo(0, 0) //注意这里必须设置为顶部不然会出现图片不全
				let that = this;
				html2canvas(document.querySelector('#all'), {//对应的dom元素id
					allowTaint: true
				}).then(function (canvas) {
					var contentWidth = canvas.width;
					var contentHeight = canvas.height;

					//一页pdf显示html页面生成的canvas高度;
					var pageHeight = contentWidth / 595.28 * 841.89;
					//未生成pdf的html页面高度
					var leftHeight = contentHeight;
					//pdf页面偏移
					var position = 0;
					//a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
					var imgWidth = 555.28;
					var imgHeight = 555.28 / contentWidth * contentHeight;

					var pageData = canvas.toDataURL('image/jpeg', 1.0);

					var pdf = new jspdf('', 'pt', 'a4');
					//有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
					//当内容未超过pdf一页显示的范围，无需分页
					if (leftHeight < pageHeight) {
						pdf.addImage(pageData, 'JPEG', 20, 0, imgWidth, imgHeight);
					} else {
						while (leftHeight > 0) {
							pdf.addImage(pageData, 'JPEG', 20, position, imgWidth, imgHeight)
							leftHeight -= pageHeight;
							position -= 841.89;
							//避免添加空白页
							if (leftHeight > 0) {
								pdf.addPage();
							}
						}
					}
					pdf.save(that.title + '.pdf');
				})
			}