pdf-lib：优点是可以控制输出内容，缺点是麻烦

html2canvas：优点是直接把html页面转成图片之后插入pdf很方便，不用过多的代码，缺点是不好控制图片大小，容易被戒断，可以把想打印的内容藏在页面外面(postion:absoult;left:-9999)

原生打印：原生浏览器打印，完全无法控制

pdfkit：尝试了一下pdfkit，一直在报错，不好用目前只有0.12.1版本能打印，但是echarts好像也放不上去，格式要求很多（字体，图片）

依赖下载

npm包下载

npm install pdf-lib
npm install jspdf
npm install html2canvas
npm install echarts
npm install @pdf-lib/fontkit

字体下载（pdf-lib使用，ttf的会用不了，得用otf的格式，第二个链接）

https://github.com/adobe-fonts/source-han-sans/tree/release/OTC
https://github.com/adobe-fonts/source-han-sans/tree/release/SubsetOTF/CN

<template>
  <div class="pdf-container">
    <el-button type="primary" @click="downloadPdf">导出 PDF</el-button>
    <el-button type="primary" @click="nativePrint">原生打印</el-button>
    <el-button type="primary" @click="downloadPdfLib"
      >导出 PDF（PDFKit）</el-button
    >
    <div ref="pdfContent" class="pdf-content">
      <div class="pdf-page">
        <div>测试</div>
        <div>测试</div>
        <div>
          测试。
        </div>
        <div ref="chartRef" id="chart" style="width: 600px; height: 280px" />
        <div>测试测试测试测试测试测试。</div>
        <div>测试测试测试测试测试测试。</div>
        <div>
         测试测试测试测试测试测试。
        </div>
        <div ref="chartRef2" id="chart" style="width: 600px; height: 280px" />
      </div>
      <div class="pdf-page">
        <div>测试测试测试测试测试测试。</div>
        <div>
          测试测试测试测试测试测试。
        </div>
        <div ref="chartRef3" id="chart" style="width: 600px; height: 280px" />
        <div>测试测试测试测试测试测试。</div>
        <div>测试测试测试测试测试测试。</div>
        <div>
         测试测试测试测试测试测试。
        </div>
        <div ref="chartRef4" id="chart" style="width: 600px; height: 280px" />
      </div>
      <div class="pdf-page">
        <div>（测试测试测试测试测试测试。</div>
        <div>
          测试测试测试测试测试测试。
        </div>
        <div ref="chartRef5" id="chart" style="width: 600px; height: 280px" />
      </div>
    </div>
  </div>
</template>

<script>
import html2canvas from "html2canvas";
import jsPDF from "jspdf";
// import PDFDocument from "pdfkit"; // 新增
import "@fontsource/noto-sans-sc";
// const PDFDocument = require("pdfkit/js/pdfkit.standalone");
export default {
  mounted() {
    this.initChart();
  },
  methods: {
    initChart() {
      const chart = this.$echarts.init(this.$refs.chartRef, "", {
        renderer: "svg", // 强制使用 SVG
        devicePixelRatio: window.devicePixelRatio || 1, // 通常设为 2（Retina 屏）或更高,这样在页面上图片不会变糊了
      });
      chart.setOption({
        title: { text: "示例 ECharts 图表" },
        tooltip: {},
        xAxis: { data: ["A", "B", "C", "D", "E"] },
        yAxis: {},
        series: [
          {
            name: "数量",
            type: "bar",
            data: [5, 20, 36, 10, 10],
          },
        ],
      });
      const chart2 = this.$echarts.init(this.$refs.chartRef2, "", {
        renderer: "svg", // 强制使用 SVG
        devicePixelRatio: window.devicePixelRatio || 1, // 通常设为 2（Retina 屏）或更高,这样在页面上图片不会变糊了
      });
      chart2.setOption({
        title: { text: "示例 ECharts 图表" },
        tooltip: {},
        xAxis: { data: ["A", "B", "C", "D", "E"] },
        yAxis: {},
        series: [
          {
            name: "数量",
            type: "bar",
            data: [5, 20, 36, 10, 10],
          },
        ],
      });

      const chart3 = this.$echarts.init(this.$refs.chartRef3, "", {
        renderer: "svg", // 强制使用 SVG
        devicePixelRatio: window.devicePixelRatio || 1, // 通常设为 2（Retina 屏）或更高,这样在页面上图片不会变糊了
      });
      chart3.setOption({
        title: { text: "示例 ECharts 图表" },
        tooltip: {},
        xAxis: { data: ["A", "B", "C", "D", "E"] },
        yAxis: {},
        series: [
          {
            name: "数量",
            type: "bar",
            data: [5, 20, 36, 10, 10],
          },
        ],
      });

      const chart4 = this.$echarts.init(this.$refs.chartRef4, "", {
        renderer: "svg", // 强制使用 SVG
        devicePixelRatio: window.devicePixelRatio || 1, // 通常设为 2（Retina 屏）或更高,这样在页面上图片不会变糊了
      });
      chart4.setOption({
        title: { text: "示例 ECharts 图表" },
        tooltip: {},
        xAxis: { data: ["A", "B", "C", "D", "E"] },
        yAxis: {},
        series: [
          {
            name: "数量",
            type: "bar",
            data: [5, 20, 36, 10, 10],
          },
        ],
      });

      const chart5 = this.$echarts.init(this.$refs.chartRef5, "", {
        renderer: "svg", // 强制使用 SVG
        devicePixelRatio: window.devicePixelRatio || 1, // 通常设为 2（Retina 屏）或更高,这样在页面上图片不会变糊了
      });
      chart5.setOption({
        title: { text: "示例 ECharts 图表" },
        tooltip: {},
        xAxis: { data: ["A", "B", "C", "D", "E"] },
        yAxis: {},
        series: [
          {
            name: "数量",
            type: "bar",
            data: [5, 20, 36, 10, 10],
          },
        ],
      });
    },
    downloadPdf() {
      const content = this.$refs.pdfContent;
      // 设置 A4 页面尺寸（宽度 210mm, 高度 297mm），以 pt 为单位（1mm ≈ 2.8346pt）
      // 使用 html2canvas 渲染时保持原始内容
      html2canvas(content, {
        allowTaint: false, // 是否允许跨域图像。会污染画布，导致无法使用canvas.toDataURL 方法
        backgroundColor: "#fff", // 画布背景色（如果未在DOM中指定）。设置null为透明
        useCORS: true, // 是否尝试使用CORS从服务器加载图像
        scale: 2, // 300 DPI = 3 × 96 DPI
        dpi: 300,
      }).then((canvas) => {
        const imgData = canvas.toDataURL("image/png");

        // 创建 jsPDF 实例并设置页面尺寸为 A4
        const pdf = new jsPDF("p", "px", "a4"); // 直接修改页面宽高

        // 获取页面宽高
        const pageWidth = pdf.internal.pageSize.getWidth();
        const pageHeight = pdf.internal.pageSize.getHeight();

        const imgWidth = pageWidth; // 设置图片宽度为 PDF 页面宽度
        const imgHeight = (canvas.height * imgWidth) / canvas.width;
        console.log(canvas, "canvas");
        console.log(pdf.internal.pageSize, "pdf.internal.pageSize");
        console.log(pageHeight, "pageHeight");
        console.log(imgHeight, "imgHeight");

        let heightLeft = imgHeight;
        let position = 0;
        let pageNum = 1;
        const totalPages = Math.ceil(imgHeight / pageHeight);

        while (heightLeft > 0) {
          if (pageNum > 1) pdf.addPage();

          // 关键修复：跳过微小残余高度
          if (heightLeft < 5) break;

          const posY = -(pageHeight * (pageNum - 1));
          pdf.addImage(imgData, "PNG", 0, posY, imgWidth, imgHeight);

          // 页码（保持原样）
          pdf.setFontSize(10);
          pdf.setTextColor(150);
          pdf.text(`${pageNum}/${totalPages}`, pageWidth / 2, pageHeight - 20, {
            align: "center",
          });

          heightLeft -= pageHeight;
          pageNum++;
        }

        pdf.save("export.pdf");
      });
    },
    nativePrint() {
      // 1. 克隆打印内容（避免影响原DOM）
      const printContent = this.$refs.pdfContent.cloneNode(true);

      // 2. 创建隐藏的打印容器
      const printContainer = document.createElement("div");
      printContainer.id = "print-container";
      printContainer.appendChild(printContent);

      // 3. 添加到DOM（隐藏状态）
      document.body.appendChild(printContainer);

      // 4. 调用打印
      window.print();

      // 5. 打印后移除临时容器
      document.body.removeChild(printContainer);
    },
    async downloadPdfLib() {
      const { PDFDocument, rgb } = await import("pdf-lib");
      const fontkit = await import("@pdf-lib/fontkit");

      const pdfDoc = await PDFDocument.create();
      pdfDoc.registerFontkit(fontkit.default);

      const fontBytes = await fetch("/SourceHanSansCN-Regular.otf").then(
        (res) => res.arrayBuffer()
      );
      const customFont = await pdfDoc.embedFont(fontBytes);
      const fontBytesBlod = await fetch("/SourceHanSansCN-Bold.otf").then(
        (res) => res.arrayBuffer()
      );
      const customFontBlod = await pdfDoc.embedFont(fontBytesBlod);
      const pageWidth = 595.28;
      const pageHeight = 841.89;
      const marginLeft = 50;
      const marginTop = pageHeight - 50;
      const fontSize = 12;
      const lineHeight = fontSize * 1.5;
      const maxTextWidth = pageWidth - marginLeft * 2;

      function splitTextToLines(text, font, size, maxWidth) {
        let lines = [];
        let currentLine = "";
        for (let i = 0; i < text.length; i++) {
          const testLine = currentLine + text[i];
          const width = font.widthOfTextAtSize(testLine, size);
          if (width < maxWidth) {
            currentLine = testLine;
          } else {
            if (currentLine) {
              lines.push(currentLine);
            }
            currentLine = text[i];
          }
        }
        if (currentLine) {
          lines.push(currentLine);
        }
        return lines;
      }

      function drawTextBlock(
        page,
        text,
        x,
        yStart,
        alignCenter = false,
        options = {}
      ) {
        const {
          fontSize = 12,
          lineHeight = fontSize * 1.5,
          color = rgb(0, 0, 0),
          font = customFont,
        } = options;

        const lines = splitTextToLines(text, font, fontSize, maxTextWidth);
        let y = yStart;
        for (const line of lines) {
          let drawX = x;
          if (alignCenter) {
            const textWidth = font.widthOfTextAtSize(line, fontSize);
            drawX = (pageWidth - textWidth) / 2;
          }

          page.drawText(line, {
            x: drawX,
            y,
            size: fontSize,
            font,
            color,
          });
          y -= lineHeight;
        }
        return y;
      }

      function addPageNumber(page, pageNumber, totalPages) {
        const fontSize = 10;
        const margin = 20;
        const pageNumberText = `${pageNumber} / ${totalPages}`;
        const textWidth = customFont.widthOfTextAtSize(
          pageNumberText,
          fontSize
        );
        page.drawText(pageNumberText, {
          x: (pageWidth - textWidth) / 2,
          y: margin,
          size: fontSize,
          font: customFont,
          color: rgb(0, 0, 0),
        });
      }

      let _this = this;
      async function drawImage(page, base64Img, x, y, width, height) {
        const canvas = await _this.convertSvgToCanvas(base64Img, 3);
        const imgData = canvas.toDataURL("image/png");
        const imgBytes = await fetch(imgData).then((res) => res.arrayBuffer());
        const pngImage = await pdfDoc.embedPng(imgBytes);
        page.drawImage(pngImage, {
          x,
          y: y - height,
          width,
          height,
        });
      }

      const generateDirectory = true;
      let y = 0;
      let directoryPage;
      if (generateDirectory) {
        directoryPage = pdfDoc.addPage([pageWidth, pageHeight]);
        let y = pageHeight - 100;

        directoryPage.drawText("目录", {
          x: marginLeft,
          y: y,
          size: 16,
          font: customFont,
          color: rgb(0, 0, 0),
        });

        y -= lineHeight;
        directoryPage.drawText(
          "一、测试测试测试测试测试测试。 .......................................... 1",
          {
            x: marginLeft,
            y: y,
            size: fontSize,
            font: customFont,
            color: rgb(0, 0, 0),
          }
        );

        y -= lineHeight;
        directoryPage.drawText(
          "二、测试测试测试测试测试测试。 .......................................... 2",
          {
            x: marginLeft,
            y: y,
            size: fontSize,
            font: customFont,
            color: rgb(0, 0, 0),
          }
        );
      }

      const page1 = pdfDoc.addPage([pageWidth, pageHeight]);
      y = marginTop;

      y = drawTextBlock(
        page1,
        "测试测试测试测试测试测试。",
        marginLeft,
        y,
        true,
        { fontSize: 16, font: customFontBlod }
      );
      y -= lineHeight / 2;
      y = drawTextBlock(page1, "一、贸易总体情况", marginLeft, y, false, {
        fontSize: 14,
      });
      y -= lineHeight / 2;
      y = drawTextBlock(
        page1,
        "    测试测试测试测试测试测试。",
        marginLeft,
        y
      );

      const chart1 = this.$echarts.getInstanceByDom(this.$refs.chartRef);
      const svgData1 = chart1.getDataURL({ type: "svg" });
      y -= lineHeight * 1.5;
      await drawImage(page1, svgData1, marginLeft, y, 495, 250);
      y -= 250 + lineHeight;

      y = drawTextBlock(page1, "二、产品结构情况", marginLeft, y, false, {
        fontSize: 14,
      });
      y -= lineHeight / 2;
      y = drawTextBlock(page1, "（一）出口商品结构", marginLeft, y);
      y -= lineHeight / 2;
      y = drawTextBlock(
        page1,
        "测试测试测试测试测试测试。",
        marginLeft,
        y
      );

      y -= lineHeight * 1.5;
      const chart2 = this.$echarts.getInstanceByDom(this.$refs.chartRef2);
      const svgData2 = chart2.getDataURL({ type: "svg" });
      await drawImage(page1, svgData2, marginLeft, y, 495, 250);
      addPageNumber(page1, 1, 3);

      const page2 = pdfDoc.addPage([pageWidth, pageHeight]);
      y = marginTop;

      y = drawTextBlock(page2, "（二）进口商品结构", marginLeft, y);
      y -= lineHeight / 2;
      y = drawTextBlock(
        page2,
        "测试测试测试测试测试测试。",
        marginLeft,
        y
      );
      const chart3 = this.$echarts.getInstanceByDom(this.$refs.chartRef3);
      const svgData3 = chart3.getDataURL({ type: "svg" });
      y -= lineHeight * 1.5;
      await drawImage(page2, svgData3, marginLeft, y, 495, 250);
      y -= 250 + lineHeight;

      y = drawTextBlock(page2, "测试测试测试测试测试测试。", marginLeft, y, false, {
        fontSize: 14,
      });
      y -= lineHeight / 2;
      y = drawTextBlock(page2, "测试测试测试测试测试测试。", marginLeft, y);
      y -= lineHeight / 2;
      y = drawTextBlock(
        page2,
        "测试测试测试测试测试测试。",
        marginLeft,
        y,
        false,
        {
          fontSize: 12,
          color: rgb(0.2, 0.2, 0.6),
          lineHeight: 20,
        }
      );

      const chart4 = this.$echarts.getInstanceByDom(this.$refs.chartRef4);
      const svgData4 = chart4.getDataURL({ type: "svg" });
      y -= lineHeight * 1.5;
      await drawImage(page2, svgData4, marginLeft, y, 495, 250);
      addPageNumber(page2, 2, 3);

      const page3 = pdfDoc.addPage([pageWidth, pageHeight]);
      y = marginTop;

      y = drawTextBlock(page3, "（二）进口商品结构", marginLeft, y);
      y -= lineHeight / 2;
      y = drawTextBlock(
        page3,
        "测试测试测试测试测试测试。",
        marginLeft,
        y
      );
      const chart5 = this.$echarts.getInstanceByDom(this.$refs.chartRef5);
      const svgData5 = chart5.getDataURL({ type: "svg" });
      y -= lineHeight * 1.5;
      await drawImage(page3, svgData5, marginLeft, y, 495, 250);
      addPageNumber(page3, 3, 3);

      const pdfBytes = await pdfDoc.save();
      const blob = new Blob([pdfBytes], { type: "application/pdf" });
      const link = document.createElement("a");
      link.href = URL.createObjectURL(blob);
      link.download = "测试测试测试测试测试测试.pdf";
      link.click();
    },

    // 将文本分割为多行
    splitTextIntoLines(text, maxWidth, font, fontSize) {
      const lines = [];
      let line = "";

      for (let i = 0; i < text.length; i++) {
        const testLine = line + text[i];
        const width = font.widthOfTextAtSize(testLine, fontSize);

        if (width < maxWidth) {
          line = testLine;
        } else {
          lines.push(line);
          line = text[i];
        }
      }

      if (line) lines.push(line);
      return lines;
    },

    // 使用 html2canvas 将 SVG 转换为 Canvas
    convertSvgToCanvas(svgData, scale = 4) {
      return new Promise((resolve, reject) => {
        const img = new Image();
        img.src = svgData;
        img.onload = () => {
          const canvas = document.createElement("canvas");
          const ctx = canvas.getContext("2d");
          // 设置canvas尺寸，使用scale来增加渲染分辨率
          canvas.width = img.width * scale;
          canvas.height = img.height * scale;
          ctx.scale(scale, scale); // 拉伸canvas，提升图像分辨率
          ctx.drawImage(img, 0, 0);
          resolve(canvas);
        };
        img.onerror = reject;
      });
    },
  },
};
</script>

<style scoped>
.pdf-container {
  background: white;
  padding: 20px;
}
.pdf-content {
  width: 794px;
  background: #fff;
  /* padding: 20px; */
  /* margin-top: 20px; */
  /* border: 1px solid #eee; */
}
.pdf-page {
  height: 1123px;
  /* border: 1px solid #eee; */
  /* margin: 10px 0; */
  padding: 20px;
}
.pdf-page:last-child {
  height: 1100px;
}
</style>