AngularJS 使用ngOption实现下拉列表

时间:2022-11-27 04:45:06

最近使用到了ngOption实现下拉选择列表,由于需要实现分组等功能,百度了下没有太好的文章,就百度到一篇英文的帖子,按照其中的代码很顺利的搞定了。

本篇根据文中代码,详细讲述下如何实现下拉列表

更多内容参考:AngularJS知识总结

下拉列表的简单使用

ng-option指令使用很简单,只需要绑定两个属性:

一个是ng-model用于获取选定的值;

另一个是ng-options用于确定下拉列表的元素数组。

<select ng-model="engineer.currentActivity" class="form-control" ng-options="act for act in activities"></select>

上面这条语句就是把选择的值与engineer.currentActivity进行双向数据绑定,然后列表中的选项是activities中的每一个值。数据如下:

$scope.engineer = {
name: "Dani",
currentActivity: "Fixing bugs"
}; $scope.activities =
[
"Writing code",
"Testing code",
"Fixing bugs",
"Dancing"
];

运行结果如:

AngularJS 使用ngOption实现下拉列表

为了美观一点,这里引用了bootstrap。

<html ng-app="myApp">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
<link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
<div ng-controller="EngineeringController" class="container">
<div class="col-md-12">
{{engineer.name}} is currently: {{ engineer.currentActivity}}
</div>
<div class="col-md-4">
<label for="name">Choose a new activity:</label>
<select ng-model="engineer.currentActivity" class="form-control"
ng-options="act for act in activities">
</select>
</div>
</div>
<script type="text/javascript">
var myAppModule = angular.module("myApp",[]);
myAppModule.controller("EngineeringController",["$scope",function($scope){
$scope.engineer = {
name: "Dani",
currentActivity: "Fixing bugs"
}; $scope.activities =
[
"Writing code",
"Testing code",
"Fixing bugs",
"Dancing"
];
}]);
</script>
</body>
</html>

复杂对象,自定义列表名称

有的时候下拉列表并不是单纯的字符串数组,可能是json对象,例如:

$scope.activities =
[
{ id: 1, type: "Work" , name: "Writing code" },
{ id: 2, type: "Work" , name: "Testing code" },
{ id: 3, type: "Work" , name: "Fixing bugs" },
{ id: 4, type: "Play" , name: "Dancing" }
];

这个时候,绑定的数据就必须是与这里面的格式相同的数据,比如直接复制其中一条:

$scope.engineer = {
name: "Dani" ,
currentActivity: {
id: 3,
type: "Work" ,
name: "Fixing bugs"
}
};

当然也可以直接指定成:

$scope.engineer = {currentActivity:activities[3]}

然后在指令中可以循环列表拼接处下拉框的名称

<select
ng-model = "engineer.currentActivity"
class="form-control"
ng-options = "a.name +' (' + a.type + ')' for a in activities" >
</select >

运行效果如:

AngularJS 使用ngOption实现下拉列表

全部的代码如下:

<html ng-app="myApp">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
<link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
<div ng-controller="EngineeringController" class="container">
<div class="col-md-12">
{{engineer.name}} is currently: {{ engineer.currentActivity}}
</div>
<div class="col-md-4">
<label for="name">Choose a new activity:</label>
<select
ng-model = "engineer.currentActivity"
class="form-control"
ng-options = "a.name +' (' + a.type + ')' for a in activities" >
</select >
</div>
</div>
<script type="text/javascript">
var myAppModule = angular.module("myApp",[]);
myAppModule.controller("EngineeringController",["$scope",function($scope){
$scope.engineer = {
name: "Dani" ,
currentActivity: {
id: 3,
type: "Work" ,
name: "Fixing bugs"
}
}; $scope.activities =
[
{ id: 1, type: "Work" , name: "Writing code" },
{ id: 2, type: "Work" , name: "Testing code" },
{ id: 3, type: "Work" , name: "Fixing bugs" },
{ id: 4, type: "Play" , name: "Dancing" }
];
}]);
</script>
</body>
</html>

实现下拉列表的分组

其实分组与前面的例子很像,只要把空间中的ng-options的值换成下面:

<select ng-model = "engineer.currentActivity"
class="form-control"
ng-options = "a.name group by a.type for a in activities" >
</select >

添加 group by 就会按照后面的值进行分组

AngularJS 使用ngOption实现下拉列表

全部代码:

<html ng-app="myApp">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
<link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
<div ng-controller="EngineeringController" class="container">
<div class="col-md-12">
{{engineer.name}} is currently: {{ engineer.currentActivity}}
</div>
<div class="col-md-4">
<label for="name">Choose a new activity:</label>
<!-- <select
ng-model = "engineer.currentActivity"
class="form-control"
ng-options = "a.name +' (' + a.type + ')' for a in activities" >
</select > -->
<select ng-model = "engineer.currentActivity"
class="form-control"
ng-options = "a.name group by a.type for a in activities" >
</select >
</div>
</div>
<script type="text/javascript">
var myAppModule = angular.module("myApp",[]);
myAppModule.controller("EngineeringController",["$scope",function($scope){
$scope.engineer = {
name: "Dani" ,
currentActivity: {
id: 3,
type: "Work" ,
name: "Fixing bugs"
}
}; $scope.activities =
[
{ id: 1, type: "Work" , name: "Writing code" },
{ id: 2, type: "Work" , name: "Testing code" },
{ id: 3, type: "Work" , name: "Fixing bugs" },
{ id: 4, type: "Play" , name: "Dancing" }
];
}]);
</script>
</body>
</html>

按照id进行标识

由于之前的ng-model相当于初始的时候给设定了一个值。当你选择一个下拉列表选项的时候,就会覆盖掉这个初始值。

所以更多的时候会使用一个id进行标识,这样在初始化赋值的时候,只需要设定一个id就可以了。

$scope.engineer = {
currentActivityId: 3
}; $scope.activities =
[
{ id: 1, type: "Work" , name: "Writing code" },
{ id: 2, type: "Work" , name: "Testing code" },
{ id: 3, type: "Work" , name: "Fixing bugs" },
{ id: 4, type: "Play" , name: "Dancing" }
];

指令可以写成下面的格式

<select
ng-model = "engineer.currentActivityId"
class="form-control"
ng-options = "a.id as a.name group by a.type for a in activities" >
</select >

通过 as 前面的值,就可以确定唯一的一个选项

AngularJS 使用ngOption实现下拉列表

全部代码如下:

<html ng-app="myApp">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="http://apps.bdimg.com/libs/angular.js/1.2.16/angular.min.js"></script>
<link rel="stylesheet" href="http://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
<div ng-controller="EngineeringController" class="container">
<div class="col-md-12">
current is: {{ engineer.currentActivityId}}
</div>
<div class="col-md-4">
<label for="name">Choose a new activity:</label>
<select
ng-model = "engineer.currentActivityId"
class="form-control"
ng-options = "a.id as a.name group by a.type for a in activities" >
</select >
</div>
</div>
<script type="text/javascript">
var myAppModule = angular.module("myApp",[]);
myAppModule.controller("EngineeringController",["$scope",function($scope){
$scope.engineer = {
currentActivityId: 3
}; $scope.activities =
[
{ id: 1, type: "Work" , name: "Writing code" },
{ id: 2, type: "Work" , name: "Testing code" },
{ id: 3, type: "Work" , name: "Fixing bugs" },
{ id: 4, type: "Play" , name: "Dancing" }
];
}]);
</script>
</body>
</html>

参考

Using ngOptions in AngularJS:http://odetocode.com/blogs/scott/archive/2013/06/19/using-ngoptions-in-angularjs.aspx