angularjs - 为 ng-options 绑定(bind)选择元素设置选定值

Question

摆弄相关代码:http://jsfiddle.net/gFCzV/7/

我正在尝试设置绑定(bind)到 ng-repeat 中引用的对象的子集合的下拉列表的选定值。我不知道如何设置选定的选项，因为我无法以我知道的任何方式引用它所绑定(bind)的集合。

HTML :

<div ng-app="myApp" ng-controller="SomeController">
    <div ng-repeat="Person in People">
        <div class="listheader">{{Person.firstName}} {{Person.lastName}}</div>
        <div class="listitem" ng-repeat="Choice in Person.Choices">
            {{Choice.Name}}: 
            <select 
                ng-model="Choice.SelectedOption"                 
                ng-options="choice.Name for choice in Choice.Options"></select>
            {{Choice.SelectedOption.ID}}
        </div>
    </div>
</div>

JS :

var myApp = angular.module('myApp', []);
myApp.controller("SomeController", function($scope) {
    $scope.People = [{
        "firstName": "John",
        "lastName": "Doe",
        "Choices": [
            {
                "Name":"Dinner",
                "Options":[{Name:"Fish",ID:1}, {Name:"Chicken",ID:2}, {Name:"Beef",ID:3}],
                "SelectedOption":{Name:"Chicken",ID:2} //this doesn't work
            },
            {
                "Name":"Lunch",
                "Options":[{Name:"Macaroni",ID:1}, {Name:"PB&J",ID:2}, {Name:"Fish",ID:3}],
                "SelectedOption":""
            }
        ],        
    }, {
        "firstName": "Jane",
        "lastName": "Doe"
    }];
});

这是我应该在模型上实际使用带有 SelectedIndex 的 ng-init 的一种情况吗？

Answer 1

如果使用 AngularJS 1.2，您可以使用“track by”来告诉 Angular 如何比较对象。

<select 
    ng-model="Choice.SelectedOption"                 
    ng-options="choice.Name for choice in Choice.Options track by choice.ID">
</select>

更新 fiddle http://jsfiddle.net/gFCzV/34/