AngularJS Select(选择框)

时间:2022-06-12 21:00:38

AngularJS 可以使用数组或对象创建一个下拉列表选项。

使用 ng-option 创建选择框

在 AngularJS 中我们可以使用 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,如下实例:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <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> <p>该实例演示了 ng-options 指令的使用。</p> </body>
</html>

ng-optionng-repeat

我们也可以使用ng-repeat 指令来创建下拉列表:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <div ng-app="myApp" ng-controller="myCtrl"> <select>
<option ng-repeat="x in names">{{x}}</option>
</select> </div> <script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.names = ["Google", "Runoob", "Taobao"];
});
</script> <p>该实例演示了使用 ng-repeat 指令来创建下拉列表。</p> </body>
</html>

ng-option与ng-repeat用哪一个来做选择框更好呢?我们倾向于使用ng-option,因为ng-repeat有局限性,选择的值是一个字符串,而使用 ng-options 指令,选择的值是一个对象,当选择值是一个对象时,我们就可以获取更多信息,应用也更灵活。

以下为二者的实例对比:

假设我们使用如下数据:

$scope.sites = [
{site : "Google", url : "http://www.google.com"},
{site : "Runoob", url : "http://www.runoob.com"},
{site : "Taobao", url : "http://www.taobao.com"}
];

使用 ng-repeat:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <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> <p>该实例演示了使用 ng-repeat 指令来创建下拉列表,选中的值是一个字符串。</p>
</body>
</html>

使用 ng-options:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <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> <p>该实例演示了使用 ng-options 指令来创建下拉列表,选中的值是一个对象。</p>
</body>
</html>

前面实例我们使用了数组作为数据源,以下我们将数据对象作为数据源。

$scope.sites = {
site01 : "Google",
site02 : "Runoob",
site03 : "Taobao"
};

ng-options 使用对象有很大的不同,使用对象作为数据源, x 为键(key), y 为值(value):

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <div ng-app="myApp" ng-controller="myCtrl"> <p>选择的网站是:</p> <select ng-model="selectedSite" ng-options="x for (x, y) in sites">
</select> <h1>你选择的值是: {{selectedSite}}</h1> </div> <p>该实例演示了使用对象作为创建下拉列表。</p> <script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.sites = {
site01 : "Google",
site02 : "Runoob",
site03 : "Taobao"
};
});
</script> </body>
</html>

你选择的值为在 key-value 对中的 value

value 在 key-value 对中也可以是个对象:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <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> </body>
</html>

在下拉菜单也可以不使用 key-value 对中的 key , 直接使用对象的属性:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://cdn.static.runoob.com/libs/angular.js/1.4.6/angular.min.js"></script>
</head>
<body> <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> </body>
</html>