你需要在 $scope $destroy 事件中解除 $scope.$on 的绑定吗? [英] Do you need to unbind $scope.$on in $scope $destroy event?

问题描述

我有使用 $on 绑定事件的指令，我需要在作用域被销毁时删除该绑定，还是自动完成?我还需要调用 $element.off 吗?

I have directive that bind event using $on do I need to remove that binding when scope is destroyed, or is it done automatically? Also do I need to call $element.off?

return {
    restrict: 'A',
    link: function($scope, $element, $attrs) {
        $element.on('load', function() {
            $element[0].contentWindow.focus();
        });
        $scope.$on('iframe:focus', function() {
            $element[0].contentWindow.focus();
        });
    }
};

推荐答案

$scope.$on() listeners 丢失时会自动销毁/清理由于 E2E 绑定在您的视图中表示.请注意，对于 $rootScope.$on() 绑定不会发生这种情况.您还可以查看 $scope AngularJS 文档.

$scope.$on() listenerers will be destroyed / cleaned up automatically when it loses its representation due to E2E binding in your view. Note that this will not happen for $rootScope.$on() bindings. You could also take a look at the $scope documentation of AngularJS.

• $scope.$on(); 会自动销毁.
• 您需要手动销毁 $rootScope.$on().

• $scope.$on(); will be destroyed automatically.
• You need to destroy $rootScope.$on() manually.

作用域销毁 - 当不再需要子作用域时，它是子作用域创建者有责任通过以下方式销毁它们scope.$destroy() API.这样做是为了停止传播$digest 调用子作用域并允许垃圾收集器要回收的子作用域模型.

Scope Destruction - When child scopes are no longer needed , it is the responsibility of the child scope creator to destroy them via scope.$destroy() API. This is done in order to stop propagation of $digest calls into the child scope and allow for memory used by the child scope models to be reclaimed by the garbage collector.

如何销毁$rootScope.$on()的例子:

//bind event
var registerScope = $rootScope.$on('someEvent', function(event) {
    console.log("fired");
});

// clean up
$scope.$on('$destroy', registerScope);

<小时>

此plnkr 将向您展示$scope.$ 的不同行为on() 和 $rootScope.$on().

通过在此 plunkr 中切换视图，控制器将重新绑定到您的视图.$rootScope.$on(); 事件会在每次切换视图时绑定，之前不会破坏视图的事件绑定.这样 $rootScope.$on() 侦听器将被堆叠/相乘.这不会发生在 $scope.$on() 绑定上，因为它会因切换视图而被破坏(丢失 DOM 中的 E2E 绑定表示).

---

This plnkr will show you the different behaviors of $scope.$on() and $rootScope.$on().

By switching the view in this plunkr the controller will be rebinded to your view. The $rootScope.$on(); event is binded every time you switch a view without destroying the event bindings of the view before. In that way the $rootScope.$on() listeners will be stacked/multiplied. This will not happen to the $scope.$on() bindings because it will be destroyed by switching the view (losing the E2E binding representation in DOM).

• $scope.$on('event'); 将监听 $scope.$broadcast('event') &$rootScope.$broadcast('event')

• $scope.$on('event'); will listen to $scope.$broadcast('event') & $rootScope.$broadcast('event')

$rootScope.$on('event'); 只会监听 $rootScope.$broadcast('event')

这篇关于你需要在 $scope $destroy 事件中解除 $scope.$on 的绑定吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！