jQuery/Js复制文本到剪贴板

<!doctype html>
<html lang="en">
 <head>
  <meta charset="UTF-8">
  <title>jQuery/Js复制文本到剪贴板</title>
  <script src="http://apps.bdimg.com/libs/jquery/1.8.3/jquery.js"></script> 
  <script type="text/javascript" src="http://www.jq22.com/demo/clipboard.js-master201703170013/dist/clipboard.min.js"></script>
 </head>
 <body>
  <div id="demo">http://www.baidu.com</div>
  <button class="btn">复制</button>
  <script>
	var content = $("#demo").html();
	var clipboard = new Clipboard('.btn', {
		text: function() {
			return content;
		}
	});
	clipboard.on('success', function(e) {
		alert("复制成功");
	});

	clipboard.on('error', function(e) {
		console.log(e);
	});
  </script>
 </body>
</html>