js实现html网页直接转pdf

<script type="text/javascript" src="./js/html2canvas.js"></script>
<script type="text/javascript" src="./js/jsPdf.debug.js"></script>
<script type="text/javascript">
var downPdf = document.getElementById("renderPdf");

downPdf.onclick = function() {
html2canvas(document.body, {
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;
//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 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('content.pdf');
}
})
}
</script>