Angular ngOptions 按对象键跟踪

Question

我想用 ngOptions 创建一个选择元素 - 到目前为止一切顺利：

<select ng-options="currency for (code, currency) in currencies track by code"
        ng-model="something.currency"></select>

现在我想通过对象键跟踪选项（因此ng-model 的值应该是键而不是对象的值）。这是否可能以某种简单的方式以及如何实现？

Answer 1

这是你要找的吗？

var myApp = angular.module('myApp',[]);

myApp.controller('GreetingController', ['$scope', function($scope) {
  $scope.currencies_old = [
    {code: "USD", curr: "$"},
    {code: "IND", curr: "INR"}
  ];
  $scope.currencies = {"USD": "USDollars", "EUR": "Euro"};
}]);

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="myApp" ng-controller="GreetingController">
<select ng-model="item" ng-options="key as value for (key , value) in currencies"></select>
Code: {{item}}
  
<br/> <br/> 
<select ng-options="item as item.curr for item in currencies_old track by item.code" ng-model="item_old"></select>
Code: {{item_old.code}}
</div>