jsPDF原理上需要先把需要保存的节点渲染到一个canvas,然后利用这个canvas制作pdf,所以需要引入两个依赖代码文件,下文中我们需要打印class名是right-asides的容器
<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>
<div class="right-asides">
hello world
</div>
<button onclick="dayin()">下载</button>
<script>
function dayin() {
var target = document.getElementsByClassName("right-asides")[0];
target.style.background = "#FFFFFF";
html2canvas(target, {
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;
//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>