html2canvas + JsPDF.js 导出pdf分页时的问题
问题描述
前一段时间 实现了html2canvas + jspdf.js 导出pdf的功能 项目当时没有测试做完就先搁置 最近项目要上线发现分页时问题 这篇文章记录一下之前的bug
import html2canvas from 'html2canvas';
import JsPDF from 'jspdf'
export function savePdf(el, title) {html2canvas(el, {useCORS: true,allowTaint: true,dpi: 192,//导出pdf清晰度scale:2,}).then(async (canvas) => {// 新建JsPDF对象const pdf = new JsPDF("p", "mm", "a4");let ctx = canvas.getContext('2d'),a4w = 192, a4h = 277, //A4大小，210mm x 297mm，四边各保留10mm的边距，显示区域190x277imgHeight = 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page = null}pdf.save(title + ".pdf");}).catch((e) => {console.log(e)}).finally(() => {});
}
分页的pdf 就能正常的展示
参考地址: https://www.cnblogs.com/BoyTNT/p/11711439.html