Angularjs 指令删除手表? [英] Angularjs directive remove watch?

问题描述

我在指令的控制器中声明了一个 $scope.$watch.当我更改页面并删除指令时，是否必须手动销毁该方式?如果是这样，我如何检测指令何时被删除?

I have a $scope.$watch declared in the controller of a directive. When I change pages and the directive is removed do I have to manually destroy the way? If so how do I detect when the directive has been removed?

推荐答案

这取决于作用域，而不是指令.如果范围被破坏，那么它的所有 $watchers 都会随之消亡.在页面更改时，您的范围会被 angular 破坏，所以您应该是安全的.

It depends on the scope, not the directive. If the scope is destroyed, then all its $watchers die with it. On page change your scope'll be destroyed by angular, so you should be safe.

当一个范围死亡时，它会产生一个 $destroy 事件.你可以看看:

When a scope dies it yields a $destroy event. You can watch it:

$scope.$on('$destroy', callback);

你可以手动从作用域中分离 $watchers，通过调用它返回的函数:

and you can manually detach $watchers from the scope, by calling the function it returns:

var sentinel = $scope.$watch('expression', callback);
sentinel(); // kill sentinel

你也可以用 $on 来做到这一点.

You can do this with $on too.

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