在 Firefox 中生成带有 jsPDF 兼容性问题的 pdf？

Question

对于 PDF 生成问题的泛滥，我们深表歉意。我一直在研究一个使用分页符将页面转换为多页 pdf（带有 jsPDF）的项目。我（终于！）让该项目在谷歌浏览器中运行，但在 Firefox 中对其进行测试时，我能够生成第一页，但后两页显示为全黑。代码如下：

$(document).ready(function() 
{
    $("#runpdf").click(function(event) 
    {
        var partsec = $("main_body page1");
        html2canvas(document.body,
        {
            logging: true,
            profile: true,
            allowTaint: true,
            letterRendering: true,
            onrendered: function(canvas) 
            {
                var sectionHeight = $("section").height();
                var sectionWidth = $("#width").width();

                var doc = new jsPDF();
                var image = new Image();
                var imageData = canvas.toDataURL("image/jpeg");
                image = Canvas2Image.convertToJPEG(canvas);
                doc.addImage(imageData,'JPEG', -115, 5, 440, 875);


                doc.addPage();

                var canvas1 = document.createElement('canvas');
                canvas1.setAttribute('height', sectionHeight);
                canvas1.setAttribute('width', sectionWidth);
                var ctx = canvas1.getContext("2d");
                ctx.drawImage(image, 0, 1025, sectionWidth, 1250, 0, 0, 1800, 950);
                var image2 = new Image();
                image2 = Canvas2Image.convertToJPEG(canvas1);
                image2Data = image2.src;
                doc.addImage(image2Data, 'JPEG', -105, 5, 440, 325);


                doc.addPage();                  
                var canvas2 = document.createElement('canvas');
                canvas2.setAttribute('height', sectionHeight);
                canvas2.setAttribute('width', sectionWidth);
                var ctx1 = canvas2.getContext("2d");
                ctx1.drawImage(image, 0, 2050, sectionWidth, 1250, 0, 0, 1800, 1000);
                var image3 = new Image();
                image3 = Canvas2Image.convertToJPEG(canvas2);
                image2Data = image3.src;
                doc.addImage(image2Data, 'JPEG', -105, 5, 440, 325);




                doc.save('test.pdf');
            }
        });
    });
});         

如您所见，每个页面都是单独生成的，并且由于第一个页面正在运行，但第二个页面没有，我假设问题出在 getContext 或 drawImage 函数上。我怎样才能改变它或添加一些东西，使它能够在 Firefox 中正常工作。 再次感谢。

Answer 1

不直接使用doc.save，可以尝试将blob保存成pdf，这里是修改后的代码

$(document).ready(function() 
{
    $("#runpdf").click(function(event) 
    {
        var partsec = $("main_body page1");
        html2canvas(document.body,
        {
            logging: true,
            profile: true,
            allowTaint: true,
            letterRendering: true,
            onrendered: function(canvas) 
            {
                var sectionHeight = $("section").height();
                var sectionWidth = $("#width").width();

                var doc = new jsPDF();
                var image = new Image();
                var imageData = canvas.toDataURL("image/jpeg");
                image = Canvas2Image.convertToJPEG(canvas);
                doc.addImage(imageData,'JPEG', -115, 5, 440, 875);


                doc.addPage();

                var canvas1 = document.createElement('canvas');
                canvas1.setAttribute('height', sectionHeight);
                canvas1.setAttribute('width', sectionWidth);
                var ctx = canvas1.getContext("2d");
                ctx.drawImage(image, 0, 1025, sectionWidth, 1250, 0, 0, 1800, 950);
                var image2 = new Image();
                image2 = Canvas2Image.convertToJPEG(canvas1);
                image2Data = image2.src;
                doc.addImage(image2Data, 'JPEG', -105, 5, 440, 325);


                doc.addPage();                  
                var canvas2 = document.createElement('canvas');
                canvas2.setAttribute('height', sectionHeight);
                canvas2.setAttribute('width', sectionWidth);
                var ctx1 = canvas2.getContext("2d");
                ctx1.drawImage(image, 0, 2050, sectionWidth, 1250, 0, 0, 1800, 1000);
                var image3 = new Image();
                image3 = Canvas2Image.convertToJPEG(canvas2);
                image2Data = image3.src;
                doc.addImage(image2Data, 'JPEG', -105, 5, 440, 325);

                var data = doc.output();
                var buffer = new ArrayBuffer(data.length);
                var array = new Uint8Array(buffer);
                for (var i = 0; i < data.length; i++) {
                  array[i] = data.charCodeAt(i);
                }

                var blob = new Blob(
                  [array],
                  {type: 'application/pdf', encoding: 'raw'}
                );
                saveAs(blob, "test.pdf");

            });
    });
});

这里使用的javascript除了jspdf还有canvas-toBlob.js和FileSaver.js