【js】HTML页面导出PDF

参考文档：https://www.cnblogs.com/alannxu/p/10982952.html

HTML

<div id="print">
      <ul class="nav nav-tabs">
        <li role="presentation" class="active"><a href="#">Home</a></li>
        <li role="presentation"><a href="#">Profile</a></li>
        <li role="presentation"><a href="#">Messages</a></li>
      </ul>

      <img width="750px;" src="http://test-admin-jdng.0752sc.cn/Public/Admin/images/background.jpg" />

      <div class="jumbotron">
        <h1>Hello, world!</h1>
        <p>This is a simple hero unit, a simple jumbotron-style component for calling extra attention to featured content or information.</p>
        <p><a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a></p>
      </div>
    </div>
    <button type="button" id="createPdf" class="btn btn-default">生成PDF</button>

核心js文件

<script  type="text/javascript" charset="utf-8"  src="js/html2canvas.js"></script>
<script  type="text/javascript" charset="utf-8" src="js/jsPdf.debug.js"></script>
<script  type="text/javascript" charset="utf-8" src="js/canvas2image.js"></script>　　

生成PDF

<script  type="text/javascript">
      $('#createPdf').on('click', function() {
        var element = $("#print");    // 这个dom元素是要导出pdf的div容器
            var w = element.width();    // 获得该容器的宽
            var h = element.height();    // 获得该容器的高
            var offsetTop = element.offset().top;    // 获得该容器到文档顶部的距离
            var offsetLeft = element.offset().left;    // 获得该容器到文档最左的距离
            var canvas = document.createElement("canvas");
            canvas.width = w * 2;    // 将画布宽&&高放大两倍
            canvas.height = h * 2;
            var context = canvas.getContext("2d");
            var scale = 2;
            context.scale(2, 2);
          //  context.translate(-offsetLeft - abs, -offsetTop);

            var opts = {
                scale: scale,
                canvas: canvas,
                 w,
                height: h,
                useCORS: true,
                background: '#FFF'
            }

            html2canvas(element, opts).then(function (canvas) {
                allowTaint: false;
                taintTest: false;
                var contentWidth = canvas.width;
                var contentHeight = canvas.height;
                //一页pdf显示html页面生成的canvas高度;
                var pageHeight = contentWidth / 592.28 * 841.89;
                //未生成pdf的html页面高度
                var leftHeight = contentHeight;
                //页面偏移
                var position = 0;
                //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
                var imgWidth = 595.28;
                var imgHeight = 592.28 / contentWidth * contentHeight;

                var pageData = canvas.toDataURL('image/jpeg', 1.0);
             //   var oCanvas = document.getElementById("print");
               // Canvas2Image.saveAsJPEG(oCanvas);
                var pdf = new jsPDF('', 'pt', 'a4');

                //有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
                //当内容未超过pdf一页显示的范围，无需分页
                if (leftHeight < pageHeight) {
                    pdf.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
                } else {    // 分页
                    while (leftHeight > 0) {
                        pdf.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
                        leftHeight -= pageHeight;
                        position -= 841.89;
                        //避免添加空白页
                        if (leftHeight > 0) {
                            pdf.addPage();
                        }
                    }
                }
                pdf.save('销售合同.pdf');
             })
      })
    </script>