AngularJS 使用ngOption实现下拉列表

时间 2019-11-11

标签 angularjs 使用 ngoption 实现下拉列表栏目 AngularJS 繁體版

原文原文链接

下拉列表的简单使用

ng-option指令使用很简单，只须要绑定两个属性：javascript

一个是ng-model用于获取选定的值；css

另外一个是ng-options用于肯定下拉列表的元素数组。html

<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，而后列表中的选项是activities中的每个值。数据以下：java

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

运行结果如：jquery

为了美观一点，这里引用了bootstrap。angularjs

View Codejson

复杂对象，自定义列表名称

有的时候下拉列表并非单纯的字符串数组，多是json对象，例如：bootstrap

$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，好比直接复制其中一条：数组

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

固然也能够直接指定成：app

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

而后在指令中能够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：

所有的代码以下：

<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

所有代码：

<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

因为以前的ng-model至关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。

因此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，只须要设定一个id就能够了。

$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" }
             ];

指令能够写成下面的格式

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

经过 as 前面的值，就能够肯定惟一的一个选项

所有代码以下：

<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