AngularJS 使用ngOption實現下拉列表

jopen 8年前發布 | 22K 次閱讀 HTML 測試技術 Web框架 angularjs

最近使用到了ngOption實現下拉選擇列表，由于需要實現分組等功能，百度了下沒有太好的文章，就百度到一篇英文的帖子，按照其中的代碼很順利的搞定了。

本篇根據文中代碼，詳細講述下如何實現下拉列表

更多內容參考：AngularJS知識總結

下拉列表的簡單使用

ng-option指令使用很簡單，只需要綁定兩個屬性：

一個是ng-model用于獲取選定的值；

另一個是ng-options用于確定下拉列表的元素數組。

<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，然后列表中的選項是activities中的每一個值。數據如下：

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

        $scope.activities =
        [
            "Writing code",
            "Testing code",
            "Fixing bugs",
            "Dancing"
        ];</pre> 

運行結果如：
  
為了美觀一點，這里引用了bootstrap。
 <html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src=";
    <link rel="stylesheet" href=";

    <script src=";
    <script src=";
</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>
View Code</pre> 
 
復雜對象，自定義列表名稱

有的時候下拉列表并不是單純的字符串數組，可能是json對象，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" }
             ]; 
 這個時候，綁定的數據就必須是與這里面的格式相同的數據，比如直接復制其中一條：

$scope.engineer = {
                 name: "Dani" ,
                 currentActivity: {
                     id: 3,
                     type: "Work" ,
                     name: "Fixing bugs"
                 }
             }; 
 當然也可以直接指定成：

$scope.engineer = {currentActivity:activities[3]} 
 然后在指令中可以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：

  
全部的代碼如下：
 <html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src=";
    <link rel="stylesheet" href=";

    <script src=";
    <script src=";
</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>
View Code</pre> 
 
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 就會按照后面的值進行分組 

  
全部代碼：
 <html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src=";
    <link rel="stylesheet" href=";

    <script src=";
    <script src=";
</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>
View Code</pre> 
 
按照id進行標識

由于之前的ng-model相當于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。
所以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，只需要設定一個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" }
         ];</pre> 

指令可以寫成下面的格式
<select 
       ng-model = "engineer.currentActivityId"
       class="form-control"
       ng-options = "a.id as a.name group by a.type for a in activities" >               
</select > 
 通過 as 前面的值，就可以確定唯一的一個選項

  
全部代碼如下：
 <html ng-app="myApp">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <script src=";
    <link rel="stylesheet" href=";

    <script src=";
    <script src=";
</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>
View Code</pre> 
 
參考

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