javascript - 使用 Javascript 生成高质量 PDF (jspdf+html2canvas)

Question

我一直在尝试通过单击页面上的按钮从 HTML 页面转换和生成 PDF，该按钮会使用两个流行的插件自动生成并强制下载该页面的 PDF* JSPDF* HTML2 Canvas 到目前为止一切正常，但生成的 PDF 总是模糊且质量不高导入 js 文件(jquery、html2canvas、jspdf)后。这是我的javascript代码

function CreatePDFfromHTML() {
    var HTML_Width = $(".html-content").width();
    var HTML_Height = $(".html-content").height();
    var top_left_margin = 15;
    var PDF_Width = HTML_Width + (top_left_margin * 2);
    var PDF_Height = (PDF_Width * 1.5) + (top_left_margin * 2);
    var canvas_image_width = HTML_Width;
    var canvas_image_height = HTML_Height;

    var totalPDFPages = Math.ceil(HTML_Height / PDF_Height) - 1;

    html2canvas($(".html-content")[0]).then(function (canvas) {
        var imgData = canvas.toDataURL("image/jpeg", 1.0);
        var pdf = new jsPDF('p', 'pt', [PDF_Width, PDF_Height]);
        pdf.addImage(imgData, 'JPG', top_left_margin, top_left_margin, canvas_image_width, canvas_image_height);
        for (var i = 1; i <= totalPDFPages; i++) { 
            pdf.addPage(PDF_Width, PDF_Height);
            pdf.addImage(imgData, 'JPG', top_left_margin, -(PDF_Height*i)+(top_left_margin*4),canvas_image_width,canvas_image_height);
        }
        pdf.save("invoice_<?php echo $trackingNumber ;?>.pdf");
        $(".html-content").hide();
    });
}

我如何调整代码使 html2canvas 将页面转换为质量更好的图像(消除模糊并使生成的 PDF 文件更好)

Answer 1

经过几天的搜索，我终于找到了一种通过将 HTML_weight 和 HTMLheight 乘以 3 来提高质量的方法，这里是新代码

function CreatePDFfromHTML() {
    var HTML_Width = $(".html-content").width()*3;
    var HTML_Height = $(".html-content").height()*3;
    var top_left_margin = 15;
    var PDF_Width = HTML_Width + (top_left_margin * 2);
    var PDF_Height = (PDF_Width * 1.5) + (top_left_margin * 2);
    var canvas_image_width = HTML_Width;
    var canvas_image_height = HTML_Height;

    var totalPDFPages = Math.ceil(HTML_Height / PDF_Height) - 1;

    html2canvas($(".html-content")[0]).then(function (canvas) {
        var imgData = canvas.toDataURL("image/jpeg", 1.0);
        var pdf = new jsPDF('p', 'pt', [PDF_Width, PDF_Height]);
        pdf.addImage(imgData, 'JPG', top_left_margin, top_left_margin, canvas_image_width, canvas_image_height);
        for (var i = 1; i <= totalPDFPages; i++) { 
            pdf.addPage(PDF_Width, PDF_Height);
            pdf.addImage(imgData, 'JPG', top_left_margin, -(PDF_Height*i)+(top_left_margin*4),canvas_image_width,canvas_image_height);
        }
        pdf.save("invoice_<?php echo $trackingNumber ;?>.pdf");
        $(".html-content").hide();
    });
}