jsPDF html 方法总是失败

Question

我正在尝试从 html 元素（div）生成包含以下内容的 PDF：

<div id = "toPDF">
<table >
  <thead>
    <tr>
      <th>Destination</th>
      <th>Start Date</th>
      <th>End Date</th>
      <th>Comment</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Dest1</td>
      <td>Date1</td>
      <td>Date2</td>
      <td>Comment1</td>
    </tr>
  </tbody>
</table>
</div>

.
.
.
<script src="https://cdnjs.cloudflare.com/ajax/libs/html2canvas/0.4.1/html2canvas.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.5.3/jspdf.debug.js" integrity="sha384-NaWTHo/8YCBYJ59830LTz/P4aQZK1sS0SneOgAvhsIl3zBu8r9RevNg5lHCHAuQ/" crossorigin="anonymous"></script>
<script src="app.js"></script>

我正在使用以下 javascript:

window.html2canvas = html2canvas;

var elem = document.getElementById('toPDF');

pdf.html(elem,
    {
        x: 20,
        y: 140,
        callback:
            function (pdf) {
                pdf.text(80, 230, "Test Text");
                var iframe = document.createElement('iframe');
                iframe.setAttribute('style', 'position:absolute;top:0;right:0;height:100%; width:600px');
                document.body.appendChild(iframe);
                iframe.src = pdf.output('datauristring');
            }
    });

生成的 PDF 显示 "Test Text"，但没有 html table 的踪迹。如果我删除 "Test Text" 输出 PDF 为空。浏览器控制台显示以下错误：

TypeError: Argument 1 of CanvasRenderingContext2D.drawImage could not be converted to any of: HTMLImageElement, SVGImageElement, HTMLCanvasElement, HTMLVideoElement, ImageBitmap

我尝试过不同的选择。我要求一个有效的 jsPDF.html() 示例。

Answer 1

问题很可能是您使用的 html2canvas 版本。 html2canvas 0.4.1 是行不通的。它应该是 html2canvas 1.0.0-alpha.11 或更高。但是，当前版本 html2canvas 1.0.0-rc.3 doesn't work either, it also gives me a blank page. At least html2canvas 1.0.0-alpha.12 仍然适用于我。

<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.5.3/jspdf.debug.js" 
        integrity="sha384-NaWTHo/8YCBYJ59830LTz/P4aQZK1sS0SneOgAvhsIl3zBu8r9RevNg5lHCHAuQ/"
        crossorigin="anonymous"></script>
<script src="~/lib/html2canvas/html2canvas.min.js"></script>
<!-- html2canvas 1.0.0-alpha.11 or html2canvas 1.0.0-alpha.12 is needed -->
<script>
    function download() {
        let pdf = new jsPDF('p', 'pt', 'a4');

        pdf.html(document.getElementById('toPDF'), {
            callback: function () {
                window.open(pdf.output('bloburl'));
            }
        });
    }
</script>

Update: the latest version that works for me is html2canvas v1.0.0-rc.1

jsPDF html 方法总是失败

jsPDF html method always fails

html

jspdf