<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="/js/angular.js1.4.6/angular.min.js"></script>
</head>
<body ng-app="">
<input ng-keyup="count = count + 1" ng-init="count=0" />
<h1>{{count}}</h1>
<p>该实例在输入框每次按键松开时，计算变量 "count" 会自动加 1。</p>
</body>
</html>