代码驿站移动版

当前位置：主页 > 网页前端 > AngularJS >

AngularJS中ng-options实现下拉列表的数据绑定方法

时间：2020-11-22 22:44:07 | 栏目：AngularJS | 点击：次

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：

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" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <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：

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" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <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

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" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <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

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" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <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>

您可能感兴趣的文章:

相关文章