在一个页面中多次使用angularjs dropDown指令，如何在单击另一个指令时关闭指令并获取该特定指令的值

<!-- DropDown指令模板 -->
<div ng-controller="DropDownController">
  <button ng-click="toggleDropDown()">Toggle DropDown</button>
  <ul ng-show="isOpen">
    <li ng-repeat="option in options" ng-click="selectOption(option)">{{ option }}</li>
  </ul>
</div>

<!-- 页面中多次使用的DropDow指令 -->
<drop-down></drop-down>
<drop-down></drop-down>
<drop-down></drop-down>

<script>
  angular.module('myApp', [])
    .controller('DropDownController', function($scope) {
      $scope.isOpen = false;
      $scope.selectedValue = '';

      $scope.toggleDropDown = function() {
        // 关闭其他指令
        var dropDowns = document.querySelectorAll('drop-down');
        for (var i = 0; i < dropDowns.length; i++) {
          dropDowns[i].controller.isOpen = false;
        }

        // 切换当前指令的状态
        $scope.isOpen = !$scope.isOpen;
      };

      $scope.selectOption = function(option) {
        $scope.selectedValue = option;
      };
    });
</script>