ionic的加载功能

下面是代码(黄色背景的是加载功能的代码):

<html ng-app="ionicApp">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no, width=device-width"> 
    
    <title>菜鸟教程(runoob.com)</title>

    <link href="http://www.runoob.com/static/ionic/css/ionic.min.css" rel="stylesheet">
    <script src="http://www.runoob.com/static/ionic/js/ionic.bundle.min.js"></script>
    <script>
    angular.module('ionicApp', ['ionic'])
    .controller('AppCtrl', function($scope, $timeout, $ionicLoading) {

      // Setup the loader
      $ionicLoading.show({
        content: 'Loading',
        animation: 'fade-in',
        showBackdrop: true,
        maxWidth: 200,
        showDelay: 0
      });
      
      // Set a timeout to clear loader, however you would actually call the $ionicLoading.hide(); method whenever everything is ready or loaded.
      $timeout(function () {
        $ionicLoading.hide();
        $scope.stooges = [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}];
      }, 2000);
      
    });
    </script>
  </head>
  <body ng-controller="AppCtrl">
    
      <ion-view title="Home">
        <ion-header-bar>
          <h1 class="title">The Stooges</h1>
        </ion-header-bar>
        <ion-content has-header="true">
          <ion-list>
            <ion-item ng-repeat="stooge in stooges" href="#">{{stooge.name}}</ion-item>
          </ion-list>
        </ion-content>
      </ion-view>
    
  </body>
</html>