带有HTML渲染器的jsPDF多页PDF

Question

我在我的网站中使用jsPDF来生成PDF.但现在我有多个DIV可以在一个PDF中打印.这可能需要2到3页.

例如:

<div id="part1">
  content
</div>

<div id="part2">
  content
</div>

<div id="part2">
   content
</div>

我的JS代码

• 这可行但不是我预期的,它添加了一部分内容(不能包含在多个页面中).
• 它删除了br,h1等html标签.

    function formtoPDF() {
      jsPDF.API.mymethod = function() {
        // 'this' will be ref to internal API object. see jsPDF source
        // , so you can refer to built-in methods like so:
        //   this.line(....)
        //   this.text(....)
      };
      var doc = new jsPDF();
      doc.mymethod();
      var pdfPart1 = jQuery('#genPDFpart1');
      var pdfPart2 = jQuery(".ltinerary");
      var pdfPart3 = jQuery("#domElementHTML");
      var specialElementHandlers = {
        '#loadVar': function(element, renderer) {
          return true;
        }
      };
      doc.fromHTML(pdfPart1.html() + pdfPart3.html() + pdfPart3.html(), 15, 15, {
        'width': 170,
        'elementHandlers': specialElementHandlers
      });
      doc.output('save', 'Download.pdf');
    }

我能解决这个问题吗？在此先感谢好朋友.

Answer 1

我有同样的工作问题.在MrRio github中搜索我发现了这个:https://github.com/MrRio/jsPDF/issues/101

基本上,您必须在添加新内容之前始终检查实际页面大小

doc = new jsPdf();
...
pageHeight= doc.internal.pageSize.height;

// Before adding new content
y = 500 // Height position of new content
if (y >= pageHeight)
{
  doc.addPage();
  y = 0 // Restart height position
}
doc.text(x, y, "value");

Answer 2

这里是一个使用html2canvas和jspdf的例子,虽然你如何生成画布并不重要 - 我们只是将它的高度用作a上的断点for loop,在其中创建一个新页面并添加内容.

在for循环之后,保存pdf.

function makePDF() {

       var quotes = document.getElementById('container-fluid');
       html2canvas(quotes)
      .then((canvas) => {
            //! MAKE YOUR PDF
            var pdf = new jsPDF('p', 'pt', 'letter');

            for (var i = 0; i <= quotes.clientHeight/980; i++) {
                //! This is all just html2canvas stuff
                var srcImg  = canvas;
                var sX      = 0;
                var sY      = 980*i; // start 980 pixels down for every new page
                var sWidth  = 900;
                var sHeight = 980;
                var dX      = 0;
                var dY      = 0;
                var dWidth  = 900;
                var dHeight = 980;

                window.onePageCanvas = document.createElement("canvas");
                onePageCanvas.setAttribute('width', 900);
                onePageCanvas.setAttribute('height', 980);
                var ctx = onePageCanvas.getContext('2d');
                // details on this usage of this function: 
                // https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Using_images#Slicing
                ctx.drawImage(srcImg,sX,sY,sWidth,sHeight,dX,dY,dWidth,dHeight);

                // document.body.appendChild(canvas);
                var canvasDataURL = onePageCanvas.toDataURL("image/png", 1.0);

                var width         = onePageCanvas.width;
                var height        = onePageCanvas.clientHeight;

                //! If we're on anything other than the first page,
                // add another page
                if (i > 0) {
                    pdf.addPage(612, 791); //8.5" x 11" in pts (in*72)
                }
                //! now we declare that we're working on that page
                pdf.setPage(i+1);
                //! now we add content to that page!
                pdf.addImage(canvasDataURL, 'PNG', 20, 40, (width*.62), (height*.62));

            }
            //! after the for loop is finished running, we save the pdf.
            pdf.save('Test.pdf');
        }
      });
    }

Answer 3

我在这个页面找到了解决方案:https://github.com/MrRio/jsPDF/issues/434 来自用户:wangzhixuan

我在这里复制解决方案://假设你的图片已经在画布中

      var imgData = canvas.toDataURL('image/png');

      /*
      Here are the numbers (paper width and height) that I found to work. 
      It still creates a little overlap part between the pages, but good enough for me.
      if you can find an official number from jsPDF, use them.
      */
      var imgWidth = 210; 
      var pageHeight = 295;  
      var imgHeight = canvas.height * imgWidth / canvas.width;
      var heightLeft = imgHeight;

      var doc = new jsPDF('p', 'mm');
      var position = 0;

      doc.addImage(imgData, 'PNG', 0, position, imgWidth, imgHeight);
      heightLeft -= pageHeight;

      while (heightLeft >= 0) {
        position = heightLeft - imgHeight;
        doc.addPage();
        doc.addImage(imgData, 'PNG', 0, position, imgWidth, imgHeight);
        heightLeft -= pageHeight;
      }
      doc.save( 'file.pdf');?

Answer 4

 var doc = new jsPDF('p', 'mm');

 var imgData = canvas.toDataURL('image/png');
 var pageHeight= doc.internal.pageSize.getHeight();
 var pageWidth= doc.internal.pageSize.getWidth();

 var imgheight = $('divName').height() * 25.4 / 96; //px to mm
 var pagecount = Math.ceil(imgheight / pageHeight);

 /* add initial page */
 doc.addPage('l','mm','a4');
 doc.addImage(imgData, 'PNG', 2, 0, pageWidth-4, 0);

 /* add extra pages if the div size is larger than a a4 size */
 if (pagecount > 0) {
     var j = 1;
     while (j != pagecount) {
         doc.addPage('l','mm','a4');
         doc.addImage(imgData, 'PNG', 2, -(j * pageHeight), pageWidth-4, 0);
         j++;
     }
 }

Answer 5

您可以使用html2canvas插件和 jsPDF 两者。处理顺序：html 到 png 和 png 到 pdf

示例代码：

jQuery('#part1').html2canvas({
    onrendered: function( canvas ) {
        var img1 = canvas.toDataURL('image/png');
    }
});
jQuery('#part2').html2canvas({
    onrendered: function( canvas ) {
        var img2 = canvas.toDataURL('image/png');
    }
});
jQuery('#part3').html2canvas({
    onrendered: function( canvas ) {
        var img3 = canvas.toDataURL('image/png');
    }
});
var doc = new jsPDF('p', 'mm');
doc.addImage( img1, 'PNG', 0, 0, 210, 297); // A4 sizes
doc.addImage( img2, 'PNG', 0, 90, 210, 297); // img1 and img2 on first page

doc.addPage();
doc.addImage( img3, 'PNG', 0, 0, 210, 297); // img3 on second page
doc.save("file.pdf");