AngularJS Select(选择框)

1、Select概述

AngularJS 中可以使用 ng-option 指令来创建一个下拉列表，列表项通过对象和数组循环输出

<div ng-app="myApp" ng-controller="myCtrl">
    <select ng-model="selectedName" ng-options="x for x in names">
    select>
div>
<script>
    var app = angular.module('myApp', []);
    app.controller('myCtrl', function($scope) {
        $scope.names = ["Google", "Runoob", "Taobao"];
    });
script>

2、数据源为对象

选择的值为在 key-value 对中的key:

<div ng-app="myApp" ng-controller="myCtrl">
    <p>选择一辆车:p>
    <select ng-model="selectedCar" ng-options="x for (x, y) in cars">
    select>

    <h1>你选择的是: {{selectedCar.brand}}h1>
    <h2>模型: {{selectedCar.model}}h2>
    <h3>颜色: {{selectedCar.color}}h3>

    <p>注意选中的值是一个对象。p>
div>

<script>
    var app = angular.module('myApp', []);
    app.controller('myCtrl', function($scope) {
        $scope.cars = {
            car01 : {brand : "Ford", model : "Mustang", color : "red"},
            car02 : {brand : "Fiat", model : "500", color : "white"},
            car03 : {brand : "Volvo", model : "XC90", color : "black"}
        }
    });
script>

选择的值为在 key-value 对中的value对象一个属性：

<div ng-app="myApp" ng-controller="myCtrl">
    <p>选择一辆车:p>
    <select ng-model="selectedCar" ng-options="y.brand for (x, y) in cars">
    select>
    <p>你选择的是: {{selectedCar.brand}}p>
    <p>型号为: {{selectedCar.model}}p>
    <p>颜色为: {{selectedCar.color}}p>
    <p>下拉列表中的选项也可以是对象的属性。p>
div>

<script>
    var app = angular.module('myApp', []);
    app.controller('myCtrl', function($scope) {
        $scope.cars = {
            car01 : {brand : "Ford", model : "Mustang", color : "red"},
            car02 : {brand : "Fiat", model : "500", color : "white"},
            car03 : {brand : "Volvo", model : "XC90", color : "black"}
        }
    });
script>

3、ng-options 与 ng-repeat

也可以使用ng-repeat 指令来创建下拉列表。
ng-repeat 指令是通过数组来循环 HTML 代码来创建下拉列表，但 ng-options 指令更适合创建下拉列表，它有以下优势：
使用 ng-options 的选项的一个对象， ng-repeat 是一个字符串。

1）ng-repeat 有局限性，选择的值是一个字符串:

<div ng-app="myApp" ng-controller="myCtrl">
    <p>选择网站:p>
    <select ng-model="selectedSite">
    <option ng-repeat="x in sites" value="{{x.url}}">{{x.site}}option>
    select>
    <h1>你选择的是: {{selectedSite}}h1>
div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
   $scope.sites = [
        {site : "Google", url : "http://www.google.com"},
        {site : "Runoob", url : "http://www.runoob.com"},
        {site : "Taobao", url : "http://www.taobao.com"}
    ];
});
script>

2）使用 ng-options 指令，选择的值是一个对象：

<div ng-app="myApp" ng-controller="myCtrl">

<p>选择网站:p>

<select ng-model="selectedSite" ng-options="x.site for x in sites">
select>

<h1>你选择的是: {{selectedSite.site}}h1>
<p>网址为: {{selectedSite.url}}p>

div>

<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
   $scope.sites = [
        {site : "Google", url : "http://www.google.com"},
        {site : "Runoob", url : "http://www.runoob.com"},
        {site : "Taobao", url : "http://www.taobao.com"}
    ];
});
script>