vue导出pdf文件

第一步安装

//页面转换成图片
npm install --save html2canvas 
//图片转换成pdf
npm install jspdf --save 

第二步在src目录下创建文件夹utils,里面创建exportPdf.js文件,把以下代码放进去

// 导出页面为PDF格式
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'

export function getPdf(title,id){
  html2Canvas(document.querySelector(`#${id}`), {
    allowTaint: true
  }).then(function (canvas) {
    let contentWidth = canvas.width
    let contentHeight = canvas.height
    let pageHeight = contentWidth / 592.28 * 841.89
    let leftHeight = contentHeight
    let position = 0
    let imgWidth = 595.28
    let imgHeight = 592.28 / contentWidth * contentHeight
    let pageData = canvas.toDataURL('image/jpeg', 1.0)
    let PDF = new JsPDF('', '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 -= 841.89
        if (leftHeight > 0) {
          PDF.addPage()
        }
      }
    }
    PDF.save(title + '.pdf')
  })
}

第三步导出pdf完整代码

 上面的方法不够完美只适用于导出一页pdf，无法解决分页内容被隔断问题，接下来提供更加完美的解决方法。

第一步

把导出的pdf页面复制一份封装成组件，在原页面中引入组件，加上定位然后top：-99999px，让组件保证在引入情况下不在可视范围之内。这样的话你想要什么样式只需要改组件中的样式即可，无需动原页面中的样式。

第二步

在子组件中引入

import html2canvas from "html2canvas"
import jsPDF from "jspdf"

在子组件中写入方法

son() {
    let that = this;
    document.body.scrollTop = document.documentElement.scrollTop = 0;
    let el = document.querySelector("#pdfHtmls");
    html2canvas(el, {
        allowTaint: true,
        useCORS: true,
        dpi: 120, // 图片清晰度问题
        background: "#FFFFFF", //如果指定的div没有设置背景色会默认成黑色,这里是个坑
        y: 0
    }).then((canvas) => {
        var currentPage = 1;
        //未生成pdf的html页面高度
        var leftHeight = canvas.height;
        var a4Width = 576;
        var a4Height = 772.89; //A4大小，210mm x 297mm，四边各保留10mm的边距，显示区域190x277
        //一页pdf显示html页面生成的canvas高度;
        var a4HeightRef = Math.floor((canvas.width / a4Width) * a4Height);
        //pdf页面偏移
        var position = 0;
        var pageData = canvas.toDataURL("image/jpeg", 1.0);
        var pdf = new jsPDF("p", "pt", "a4"); //A4纸，纵向
        var index = 1,
        canvas1 = document.createElement("canvas"),
        height;
        pdf.setDisplayMode("fullwidth", "continuous", "FullScreen");
        function createImpl(canvas) {
            console.log(leftHeight, a4HeightRef);
            if (leftHeight > 0) {
                index++;
                var checkCount = 0;
                if (leftHeight > a4HeightRef) {
                    var i = position + a4HeightRef;
                    for (i = position + a4HeightRef; i >= position; i--) {
                        var isWrite = true;
                        for (var j = 0; j < canvas.width; j++) {
                            var c = canvas
                                .getContext("2d")
                                .getImageData(j, i, 1, 1).data;
                            if (c[0] != 0xff || c[1] != 0xff || c[2] != 0xff) {
                                isWrite = false;
                                break;
                            }
                        }
                        if (isWrite) {
                            checkCount++;
                            if (checkCount >= 10) {
                                break;
                            }
                        } else {
                            checkCount = 0;
                        }
                    }
                    height =
                        Math.round(i - position) || Math.min(leftHeight, a4HeightRef);
                    if (height <= 0) {
                        height = a4HeightRef;
                    }
                } else {
                    height = leftHeight;
                }
                canvas1.width = canvas.width;
                canvas1.height = height;
                var ctx = canvas1.getContext("2d");
                ctx.drawImage(
                    canvas,
                    0,
                    position,
                    canvas.width,
                    height,
                    0,
                    0,
                    canvas.width,
                    height
                );
                var pageHeight = Math.round((a4Width / canvas.width) * height);
                if (position != 0) {
                    pdf.addPage();
                }
                pdf.addImage(
                    canvas1.toDataURL("image/jpeg", 1.0),
                    "JPEG",
                    10,
                    40,
                    a4Width,
                    (a4Width / canvas1.width) * height
                );
                leftHeight -= height;
                position += height;
                if (leftHeight > 0) {
                    setTimeout(createImpl, 500, canvas);
                } else {
                    pdf.save(that.title + ".pdf");
                }
            }
        }
        let targetPage = pdf.internal.getNumberOfPages();
        //当内容未超过pdf一页显示的范围，无需分页
        if (leftHeight < a4HeightRef) {
            pdf.addImage(
                pageData,
                "JPEG",
                10,
                40,
                a4Width,
                (a4Width / canvas.width) * leftHeight
            );
            pdf.save(that.title + ".pdf");
        } else {
            try {
                pdf.deletePage(0);
                setTimeout(createImpl, 500, canvas);
            } catch (err) {
            }
        }
    })
}

第三步

在父页面中调用子组件的方法即可

exportPDF() {
   this.$refs.child.son()
}