在angular中实现下拉框的两种方式 ng-repeat和 ng-option

1. ng-repeat实现下拉框：

select下拉框里option组装成下拉框，这里利用ng-repeat指令来创建

实现源码

<!DOCTYPE html> 
<html> 
<head> 
<meta charset="UTF-8"> 
<title>AngularJS之下拉框（方式二）</title> 
<script type="text/javascript" src="../js/angular.min.js" ></script> 
<script> 
var app = angular.module("secondApp",[]); 
app.controller("secondCon",function($scope){ 
$scope.trees = ["松树","樟树","枫树","枣树","桃树"]; 
}); 
</script> 
</head> 
<body> 
<div ng-app="secondApp" ng-controller="secondCon"> 
<select style=" 200px;"> 
<option ng-repeat="tree in trees">{{tree}}</option> 
</select> 
</div> 
</body> 
</html>

2.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"
            ];