更改常量值并广播到angular 1.4.9中的子控制器

angular.module('myApp', [])
  .constant('myConstant', 'Initial Value');

angular.module('myApp')
  .controller('ParentController', function($scope, myConstant) {
    $scope.constantValue = myConstant;
    
    $scope.changeConstant = function() {
      myConstant = 'New Value';
      $scope.constantValue = myConstant;
      $scope.$broadcast('constantChanged', myConstant);
    };
  });

angular.module('myApp')
  .controller('ChildController', function($scope) {
    $scope.$on('constantChanged', function(event, data) {
      $scope.constantValue = data;
    });
  });