63 lines
2.3 KiB
JavaScript
63 lines
2.3 KiB
JavaScript
// 页面导出为pdf格式
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import html2Canvas from 'html2canvas';
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import jsPDF from 'jspdf';
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const htmlToPdf = {
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getPdf(title, id) {
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html2Canvas(
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document.querySelector(id),
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{
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allowTaint: false,
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taintTest: false,
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logging: false,
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useCORS: true,
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dpi: window.devicePixelRatio * 4, //将分辨率提高到特定的DPI 提高四倍
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scale: 4, //按比例增加分辨率
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}
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).then((canvas) => {
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var pdf = new jsPDF('p', 'mm', 'a4'); //A4纸，纵向
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var ctx = canvas.getContext('2d'),
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a4w = 190,
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a4h = 272, //A4大小，210mm x 297mm，四边各保留10mm的边距，显示区域190x277
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imgHeight = Math.floor((a4h * canvas.width) / a4w), //按A4显示比例换算一页图像的像素高度
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renderedHeight = 0;
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while (renderedHeight < canvas.height) {
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var page = document.createElement('canvas');
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page.width = canvas.width;
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page.height = Math.min(imgHeight, canvas.height - renderedHeight); //可能内容不足一页
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//用getImageData剪裁指定区域，并画到前面创建的canvas对象中
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page
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.getContext('2d')
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.putImageData(
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ctx.getImageData(
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0,
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renderedHeight,
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canvas.width,
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Math.min(imgHeight, canvas.height - renderedHeight),
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),
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0,
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0,
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);
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pdf.addImage(
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page.toDataURL('image/jpeg', 1.0),
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'JPEG',
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10,
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10,
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a4w,
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Math.min(a4h, (a4w * page.height) / page.width),
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); //添加图像到页面，保留10mm边距
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renderedHeight += imgHeight;
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if (renderedHeight < canvas.height) {
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pdf.addPage(); //如果后面还有内容，添加一个空页
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}
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// delete page;
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}
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pdf.save(title + '.pdf')
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});
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},
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};
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export default htmlToPdf; |