js 将元素的内容保存图片

<!-- 引用插件 -->
<script type="text/javascript" src="http://html2canvas.hertzen.com/dist/html2canvas.js"></script> 

html2canvas($(".center"), { 
onrendered: function(canvas) {
//将图片保存到变量
var image = canvas.toDataURL("image/jpeg");

});