windLifecontrolPro/src/views/generatingCapacity/report/fixGetPDF.js

/*
 * @Author: 蒋珅 11455645+jiang-shena@user.noreply.gitee.com
 * @Date: 2023-06-12 18:13:48
 * @LastEditors: 蒋珅 11455645+jiang-shena@user.noreply.gitee.com
 * @LastEditTime: 2023-06-13 16:26:14
 * @FilePath: \PowerAnalysis\src\pages\report\fixGetPDF.js
 * @Description: 这是默认设置,请设置`customMade`, 打开koroFileHeader查看配置 进行设置: https://github.com/OBKoro1/koro1FileHeader/wiki/%E9%85%8D%E7%BD%AE
 */
// 页面导出为pdf格式
import html2Canvas from 'html2canvas';
import jsPDF from 'jspdf';
const htmlToPdf = {
    getPdf( loading,title,) {
        let dom = document.querySelector('#pdfDom')
        let theme = dom.className ==='block' ? false : true
        html2Canvas(document.querySelector('#pdfDom'), {
        allowTaint: false,
        taintTest: false,
        logging: false,
        useCORS: true,
        dpi: window.devicePixelRatio * 4, //将分辨率提高到特定的DPI 提高四倍
        scale: 4, //按比例增加分辨率
        }).then((canvas) => {
            var pdf = new jsPDF('p', 'mm', 'a4'); //A4纸，纵向
            if (!theme) { 
                pdf.setDrawColor(4, 12, 11);
                pdf.rect(0, 0, pdf.internal.pageSize.getWidth(), pdf.internal.pageSize.getHeight(), 'F');
            }
            var ctx = canvas.getContext('2d'),
                a4w = 190,
                a4h = 272, //A4大小，210mm x 297mm，四边各保留10mm的边距，显示区域190x277
                imgHeight = 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) {
            var 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
                if (!theme) { 
                    pdf.setDrawColor(4, 12, 11);
                    pdf.rect(0, 0, pdf.internal.pageSize.getWidth(), pdf.internal.pageSize.getHeight(), 'F');
                }
            }
            // delete page;
        }
        //保存文件
        pdf.save('发电能力分析' + '.pdf');
        // loading = false;
        console.log(loading);
        });
    },
};

export default htmlToPdf;