javascript Angularjs $broadcast 一次，$on 两次
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Angularjs $broadcast once, $on twice
提问by Shai M.
It sends $broadcast once from the rootScope, but the listener ($on) gets called twice.
它从 rootScope 发送一次 $broadcast，但监听器 ($on) 被调用两次。
The listener is in a controller and it uses $rootScope.$oninstead of $scope.$on. Has someone had this problem?
侦听器位于控制器中，它使用$rootScope.$on而不是$scope.$on. 有人遇到过这个问题吗？
edit
编辑
rootScope:
根范围：
$rootScope.$broadcast('menuActivateAction' + item.event_name_postfix, item.event_args);
other Controller:
其他控制器：
$rootScope.$on('menuActivateActionPublish', function(event) {});
回答by Tomas
Since you register your $on listener on $rootScope, it doesn't get destroyed with the controller and next time you init the controller it gets created again.
由于您在 $rootScope 上注册了 $on 侦听器，因此它不会被控制器销毁，下次您初始化控制器时，它会再次创建。
You should create your listener on controller scope
您应该在控制器范围内创建您的侦听器
$scope.$on('menuActivateActionPublish', function(event) {});
回答by que1326
Be careful you avoid two instances of the controller means two event listeners, which means the method gets executed twice !! ( example: using twice 'ng-controller' )
小心你避免控制器的两个实例意味着两个事件监听器，这意味着该方法被执行两次！！（例如：使用两次 'ng-controller' ）
回答by Jo?o Otero
To complement que1326 answer, as an example, if you are using ui-router and have something like
为了补充 que1326 的答案，例如，如果您使用 ui-router 并且有类似的东西
.state('app.yourpage', {
url:'yourPage',
views: {
'content@': {
templateUrl : 'views/yourPage.html',
controller : 'YourController'
}
}
})
and in yourPage.html you have a ng-controller="YourController as Ctrl", then you are creating 2 instances of the controller: 1 instance is created by the state configuration and another one in your html.
在 yourPage.html 中，您有一个ng-controller="YourController as Ctrl"，然后您正在创建控制器的 2 个实例：1 个实例由状态配置创建，另一个在您的 html 中。
回答by CommandoScorch
The only solution I could get to work was to create the listener inside the $viewContentLoaded event:
我可以开始工作的唯一解决方案是在 $viewContentLoaded 事件中创建侦听器：
$scope.$on('$viewContentLoaded', function() {
//Put your listener(s) in here
$scope.$on('menuActivateActionPublish', function(event) {});
});
