vue3 实现将页面生成 pdf 导出（html2Canvas + jspdf）

效果图：

需求：（报表页面等)导出为pdf

1、安装依赖

javascript 复制代码

npm i html2canvas
npm i jspdf

2、在utils文件夹下新建html2pdf.ts文件

TypeScript 复制代码

import html2canvas from 'html2canvas';
import jsPDF from 'jspdf'
 
export const htmlToPDF = async (htmlId: string, title: string = "标题", bgColor = "#fff") => {
  let pdfDom: HTMLElement | null = document.getElementById(htmlId) as HTMLElement
  pdfDom.style.padding = '0 10px !important'
  const A4Width = 595.28;
  const A4Height = 841.89;
  let canvas = await html2canvas(pdfDom, {
    scale: 2,
    useCORS: true,
    backgroundColor: bgColor,
  });
  let pageHeight = (canvas.width / A4Width) * A4Height;
  let leftHeight = canvas.height;
  let position = 0;
  let imgWidth = A4Width;
  let imgHeight = (A4Width / canvas.width) * canvas.height;
  /*
     根据自身业务需求  是否在此处键入下方水印代码
    */
  let pageData = canvas.toDataURL("image/jpeg", 1.0);
  let PDF = new jsPDF("p", '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 -= A4Height;
      if (leftHeight > 0) PDF.addPage();
    }
  }
  PDF.save(title + ".pdf");
}

如果你想给pdf加上水印，则添加下面这段代码：

TypeScript 复制代码

const ctx: any = canvas.getContext('2d');
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.rotate((20 * Math.PI) / 180);
ctx.font = '20px Microsoft Yahei';
ctx.fillStyle = 'rgba(184, 184, 184, 0.8)';
for (let i = canvas.width * -1; i < canvas.width; i += 240) {
  for (let j = canvas.height * -1; j < canvas.height; j += 200) {
    // 填充文字，x 间距, y 间距
    ctx.fillText('水印名', i, j);
  }
}

3、在目标页面引入方法即可

html 复制代码

<template>
  <div id="test-id">
    <TestPinia></TestPinia>
  </div>
  <button @click="() => htmlToPDF('test-id', 'test pdf')">导出</button>
</template>

<script lang="ts">
import { defineComponent } from "vue";

import TestPinia from "@/views/BarChart03/index.vue";
import { htmlToPDF } from "@/utils/pdf/html2pdf";

export default defineComponent({
  name: "App",
  components: {
    TestPinia,
  },
  setup() {
    return {
      htmlToPDF,
    };
  },
});
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>