javascript - 如何将 png Canvas 图像下载为 PDF JQuery

Question

这段代码我写了很多次，下载 png 格式的图像。现在我需要将图像下载为 pdf，我不知道如何在不改变太多代码结构的情况下执行此实现。有人可以帮我这个忙吗？非常感谢。

我的 JQuery:

function genScreenshot() {
                html2canvas(document.getElementById('boxes'), {
                    onrendered: function(canvas) {
                        $('#container').html("");
                        $('#container').append(canvas);

                        if (navigator.userAgent.indexOf("MSIE ") > 0 || 
                            navigator.userAgent.match(/Trident.*rv\:11\./)) 
                        {
                            var blob = canvas.msToBlob();
                            window.navigator.msSaveBlob(blob,'yuppy.png');
                        }
                        else {
                            $('#test').attr('href', canvas.toDataURL("image/png"));
                            $('#test').attr('download','yuppy.png');
                            $('#test')[0].click();
                        }
                    }
                });
            }

实现代码示例:

html2canvas($("#canvas"), {
            onrendered: function(canvas) {         
                var imgData = canvas.toDataURL(
                    'image/png');              
                var doc = new jsPDF('p', 'mm');
                doc.addImage(imgData, 'PNG', 10, 10);
                doc.save('sample-file.pdf');
            }
        });

Answer 1

你可以适应this answer到您的代码，使用 jsPDF:

JS

$('#test').click(genScreenshot);

function genScreenshot() {
    html2canvas(document.getElementById('boxes'), {
        onrendered: function(canvas) {
            $('#container').html("");
            $('#container').append(canvas);

            var imgData = canvas.toDataURL("image/jpeg", 1.0);
            var pdf = new jsPDF();

            pdf.addImage(imgData, 'JPEG', 0, 0);

            pdf.save('screenshot.pdf');
        }
    });
}

CSS

#boxes {
  background: #fff; /* To avoid a black background in PDF */
}

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/html2canvas/0.4.1/html2canvas.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.3.2/jspdf.min.js"></script>

<div id="boxes">
  <h1>This is some content for the screenshot</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Repudiandae asperiores est autem corporis natus nesciunt veritatis, ullam inventore distinctio, quisquam nam quis temporibus vero, fugiat tempore officia. Laborum, harum, alias.</p>
</div>

<button id="test">Download as PDF</button>

<div id="container"></div>

Note: I only tested this in Chrome, Edge and Firefox on Windows 10. You might want to try other browsers/systems.