// 新建exportPDF.js文件import html2canvas from 'html2canvas'; import jsPDF from 'jspdf';
function generatePDF(id, title) { //下载pdf方法 let demo = document.getElementById(id); demo.style.overflow = 'visible'; html2canvas(demo, { allowTaint: true, //允许跨域 height: document.getElementById(id).scrollHeight, // width: document.getElementById(id).scrollWidth, //为了使横向滚动条的内容全部展示,这里必须指定 background: "#FFFFFF", //如果指定的div没有设置背景色会默认成黑色 // dpi: 300, scale: 1.5, useCORS: true, //允许canvas画布内 可以跨域请求外部链接图片, 允许跨域请求。 }).then((canvas) => { console.log(canvas, 'canvas') let pdf = new jsPDF('p', 'mm', 'a4'); //A4纸,纵向 let ctx = canvas.getContext('2d'), a4w = 190, a4h = 277, //A4大小,210mm x 297mm,四边各保留10mm的边距,显示区域190x277 imgHeight = Math.floor(a4h * canvas.width / a4w), //按A4显示比例换算一页图像的像素高度 renderedHeight = 0;
while (renderedHeight < canvas.height) { let page = document.createElement("canvas"); page.width = canvas.width; page.height = Math.min(imgHeight, canvas.height - renderedHeight); //可能内容不足一页 //用getImageData剪裁指定区域,并画到前面创建的canvas对象中 page.getContext('2d').putImageData(ctx.getImageData(0, renderedHeight, canvas.width, Math.min( imgHeight, canvas.height - renderedHeight)), 0, 0); pdf.addImage(page.toDataURL('image/jpeg', 1.0), 'JPEG', 10, 10, a4w, Math.min(a4h, a4w * page.height / page.width)); //添加图像到页面,保留10mm边距 renderedHeight += imgHeight; if (renderedHeight < canvas.height) pdf.addPage(); //如果后面还有内容,添加一个空页 } pdf.save(title + '.pdf'); }) demo.style.overflow = 'auto'; }
export { generatePDF };
// 新建index.jsx文件,引用generatePDFimport { generatePDF } from "@/utils/exportPDF"; return ( <div> <Button onClick={() => { generatePDF("contentPage", "导出pdf文件的名字"); }} >导出PDF</Button> <div style={{ height: '100vh' }} id="contentPage"> // 页面内容 </div> </div> )
标签:jspdf,react,canvas,renderedHeight,height,html2canvas,width,pdf,page From: https://www.cnblogs.com/lou-0820/p/17390001.html