AngularJS 使用ngOption實現下拉列表

時間 2019-11-11

標籤 angularjs 使用 ngoption 實現下拉列表欄目 AngularJS 简体版

原文原文鏈接

下拉列表的簡單使用

ng-option指令使用很簡單，只須要綁定兩個屬性：javascript

一個是ng-model用於獲取選定的值；css

另外一個是ng-options用於肯定下拉列表的元素數組。html

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

上面這條語句就是把選擇的值與engineer.currentActivity進行雙向數據綁定，而後列表中的選項是activities中的每個值。數據以下：java

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

運行結果如：jquery

爲了美觀一點，這裏引用了bootstrap。angularjs

View Codejson

複雜對象，自定義列表名稱

有的時候下拉列表並非單純的字符串數組，多是json對象，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" }
             ];

這個時候，綁定的數據就必須是與這裏面的格式相同的數據，好比直接複製其中一條：數組

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

固然也能夠直接指定成：app

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

而後在指令中能夠循環列表拼接處下拉框的名稱

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

運行效果如：

所有的代碼以下：

<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>

實現下拉列表的分組

其實分組與前面的例子很像，只要把空間中的ng-options的值換成下面：

<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 就會按照後面的值進行分組

所有代碼：

<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進行標識

因爲以前的ng-model至關於初始的時候給設定了一個值。當你選擇一個下拉列表選項的時候，就會覆蓋掉這個初始值。

因此更多的時候會使用一個id進行標識，這樣在初始化賦值的時候，只須要設定一個id就能夠了。

$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" }
             ];

指令能夠寫成下面的格式

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

經過 as 前面的值，就能夠肯定惟一的一個選項

所有代碼以下：

<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>