获取默认的第一子路由angularjs

angular.module('myApp', ['ui.router'])
  .config(function($stateProvider, $urlRouterProvider) {
    $stateProvider
      .state('home', {
        url: '/home',
        templateUrl: 'home.html',
        controller: 'HomeController'
      })
      .state('about', {
        url: '/about',
        templateUrl: 'about.html',
        controller: 'AboutController'
      })
      .state('contact', {
        url: '/contact',
        templateUrl: 'contact.html',
        controller: 'ContactController'
      });

    $urlRouterProvider.otherwise('/home');
  });

angular.module('myApp')
  .controller('HomeController', function($scope, $state) {
    $scope.defaultChildRoute = $state.current.children[0].name;
  });