前端将html导出pdf文件解决分页问题

1.安装依赖

    npm install jspdf html2canvas

2.使用方法

    import htmlToPdffrom './index.js'    const suc = () => {  message.success('success');};    //记得在需要打印的p上面添加 id  let dom = document.querySelector('#testPdf');  let pdf = new htmlToPdf(dom, '测试', 'splitPages', ',', suc, 2);  pdf.outPutPdfFn('测试');

3.使用说明

 //splitPages 是需要添加的类名，需要再那个地方分页就在那个地方添加类名 splitPages     //如：                                         

导出效果：

具体代码 ：

import jsPDF from "jspdf";import html2canvas from "html2canvas";/** 使用说明* ele:需要导出pdf的容器元素(dom节点 不是id)* pdfFileName: 导出文件的名字 通过调用outPutPdfFn方法也可传参数改变* splitClassName: 避免分段截断的类名 当pdf有多页时需要传入此参数 , 避免pdf分页时截断元素  如表格* breakClassName:自定义分页符类名，默认为break_page,添加改类名的标签被自动分页到下一页* sucCallback：成功回调函数* scale：增强图片清晰度 数字也打越清晰* 调用方式 先 let pdf = new htmlToPdf(ele, 'pdf' ,'itemClass');* 若想改变pdf名称 pdf.outPutPdfFn(fileName);  outPutPdfFn方法返回一个promise 可以使用then方法处理pdf生成后的逻辑* */class htmlToPdf {    constructor(ele, pdfFileName, splitClassName = "itemClass", breakClassName = "break_page", sucCallback = () => { }, scale = 2) {        this.ele = ele;        this.pdfFileName = pdfFileName;        this.splitClassName = splitClassName;        this.breakClassName = breakClassName;        this.sucCallback = sucCallback;        this.scale = scale;        this.A4_WIDTH = 595;        this.A4_HEIGHT = 842;        this.pageHeight = 0        this.pageNum = 1    };    async getPDF(resolve) {        let ele = this.ele;        let pdfFileName = this.pdfFileName        let eleW = ele.offsetWidth // 获得该容器的宽        let eleH = ele.scrollHeight // 获得该容器的高        let eleOffsetTop = ele.offsetTop // 获得该容器到文档顶部的距离        let eleOffsetLeft = ele.offsetLeft // 获得该容器到文档最左的距离        let canvas = document.createElement("canvas")        let abs = 0        let win_in = document.documentElement.clientWidth || document.body.clientWidth // 获得当前可视窗口的宽度（不包含滚动条）        let win_out = window.innerWidth // 获得当前窗口的宽度（包含滚动条）        if (win_out > win_in) {            abs = (win_out - win_in) / 2 // 获得滚动条宽度的一半        } canvas.width = eleW * 2 // 将画布宽&&高放大两倍        canvas.height = eleH * 2        let context = canvas.getContext("2d")        context.scale(this.scale, this.scale) // 增强图片清晰度        context.translate(- eleOffsetLeft - abs, - eleOffsetTop)        html2canvas(ele, {            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(async canvas => {            let contentWidth = canvas.width            let contentHeight = canvas.height            // 一页pdf显示html页面生成的canvas高度;            this.pageHeight = (contentWidth / this.A4_WIDTH) * this.A4_HEIGHT            // 这样写的目的在于保持宽高比例一致 this.pageHeight/canvas.width = a4纸高度/a4纸宽度// 宽度和canvas.width保持一致            // 未生成pdf的html页面高度            let leftHeight = contentHeight            // 页面偏移            let position = 0            // a4纸的尺寸[595,842],单位像素，html页面生成的canvas在pdf中图片的宽高            let imgWidth = this.A4_WIDTH - 10 // -10为了页面有右边距            let imgHeight = (this.A4_WIDTH / contentWidth) * contentHeight            let pageData = canvas.toDataURL("image/jpeg", 1.0)            let pdf = 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  0) {                    pdf.addImage(pageData, "JPEG", 6, position + 40, imgWidth - 12, imgHeight - 80)                    leftHeight -= this.pageHeight                    position -= this.A4_HEIGHT                    // 避免添加空白页                    if (leftHeight > 0) {                        pdf.addPage()                    }                }            } pdf.save(pdfFileName + ".pdf", { returnPromise: true }).then(() => { // 去除添加的空p 防止页面混乱                let doms = document.querySelectorAll('.emptyDiv')                for (let i = 0; i  { // 进行分割操作，当dom内容已超出a4的高度，则将该dom前插入一个空dom，把他挤下去，分割            let target = this.ele;            this.pageHeight = target.scrollWidth / this.A4_WIDTH * this.A4_HEIGHT;            this.ele.style.height = 'initial';            pdfFileName ? this.pdfFileName = pdfFileName : null;            this.pageNum = 1; // pdf页数            this.domEach(this.ele)            // 异步函数，导出成功后处理交互            this.getPDF(resolve, reject);        })    };    domEach(dom) {        let childNodes = dom.childNodes        childNodes.forEach((childDom, index) => {            if (this.hasClass(childDom, this.splitClassName)) {                let node = childDom;                let eleBounding = this.ele.getBoundingClientRect();                let bound = node.getBoundingClientRect();                let offset2Ele = bound.top - eleBounding.top                let currentPage = Math.ceil((bound.bottom - eleBounding.top) / this.pageHeight); // 当前元素应该在哪一页                if (this.pageNum  -1;    }}export default htmlToPdf;