html js html转pdf html2pdf 图片生成内容不全

js依赖导入：

<script src="https://cdn.bootcss.com/html2canvas/0.5.0-beta4/html2canvas.js"></script>
<script src="https://cdn.bootcss.com/jspdf/1.3.4/jspdf.debug.js"></script>

    

    //wrapper 需要生成pdf的容器ID
    var targetDom = $("#wrapper");
    var copyDom = targetDom.clone().attr('id','content');

    copyDom.width(targetDom.width() + "px");
    $('body').append(copyDom);

    html2canvas(copyDom,{
            background:"#fff",
            dpi: 192,//导出pdf清晰度
            scale:2,
            onrendered: function (canvas) {
                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;
                //pdf页面偏移
                var position = 0;
                //html页面生成的canvas在pdf中图片的宽高（a4纸的尺寸[595.28,841.89]）
                var imgWidth = 595.28;
                var imgHeight = 592.28 / contentWidth * contentHeight;
                var pageData = canvas.toDataURL('image/jpeg', 1.0);
                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 {
                    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('pdf名称.pdf');
                copyDom.remove()
            },
        });
}