Angular JS:在 ng-change 上获取 ng-model [英] Angular JS: get ng-model on ng-change

问题描述

我有以下 HTML

<select ng-model="country" ng-options="c.name for c in countries" ng-change="filterByCountry"></select>

这是由以下带有国家/地区列表的对象提供的

That is beeing fed by the following object with a list of countries

$scope.countries = [{name:Afeganistão, country:AF}, {name:África do Sul, country:ZA}, name:Albânia, country:AL}, {name:Alemanha, country:DE}, {name:Andorra, country:AD} ...];

当我更改下拉值时，我希望我的模型 ($scope.country) 在 filterByCountry 函数内更新，但事实并非如此.我在这里错过了什么?

When I change my dropdown value I was expecting my model ($scope.country) to be updated, inside filterByCountry function, but it isn't. What am I missing here?

推荐答案

ng-change 处理程序在 ng-model 实际更新之前被触发.如果您希望 filterByCountry 在每次 $scope.country 更改时触发(而不是仅在下拉列表更改时)，您应该使用以下代码:

The ng-change handler is fired before the ng-model is actually updated. If you want filterByCountry to be fired every time $scope.country changes (rather than just when the dropdown changes), you should use the following instead:

$scope.$watch('country', filterByCountry);

我总是发现在可能的情况下对 $scope 中的变化做出反应比对 DOM 事件做出反应更有用.

I always find it more useful to react to changes in my $scope rather than DOM events when possible.

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