输入无线电ng-model没有更新

我试图解决一个谜题，为什么输入[无线电]控件的ng模型没有像我期望的那样设置。当页面加载时，所有无线电都被正确启动。单击不同的控件会改变radioVal变量——它的值会在页面中呈现。

问题在于它看起来只发生在DOM中。当我调试代码时，$scope.radioVal总是相同的…modalDialog的隔离作用域不包含radioVal属性。

在哪个范围内创建无线电ng-model ?这是一个不同的例子吗?

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工作代码可以在jsfiddle上找到。

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我的html代码是:

<div ng-app = "app"> 
 <div ng-controller="mainCtrl">         
   <a ng-click="showModalDlg()">Click me</a>
   <br/><br/>
   <modal-dialog show="showModal" action="actionFun">                        
    <form>
      <input type="radio" ng-model="radioVal" value="1">One<br/>
      <input type="radio" ng-model="radioVal" value="nothing changes me">Two<br/>
      <input type="radio" ng-model="radioVal" value="3">Three<br/>
          <br/><br/>
          The model changes in the DOM as expected: <b>radioVal = {{radioVal | json}}</b>
          <br/>
          but by pressing the Action button you can see that the model has not been modified. 
    </form>                        
    <a class="button" action>Action</a>                     
    </modal-dialog>
   </div>
</div>

我的angular代码:

angular.module('common', [])
    .controller('mainCtrl', ['$scope', function($scope){
        $scope.showModal = false;
        $scope.radioVal = "nothing changes me";
        $scope.showModalDlg = function() {
           $scope.showModal = !$scope.showModal;
        };
        $scope.actionFun = function() {
           console.log('actionFun ...' + $scope.radioVal);
        };        
    }]).directive('modalDialog',
        function () {
            return {
               restrict: 'E',
               scope: {
                  show: '=',
                  action: '&',
               },
               replace: true,
               transclude: true,
               link: function (scope, element, attrs) {
                        scope.hideModal = function () {
                           scope.show = false;
                           scope.$apply();
                        };
                        $('a[hide]', element).on('click', function(){
                           scope.hideModal();
                        });
                        $('a[action]', element).on('click', function(){
                           console.log('There is no radioVal in isolated scope either ... ' + scope.radioVal);
                           scope.action()();
                           scope.hideModal();
                        });
                  },
            template: '<div class=''ng-modal'' ng-show=''show''><div class=''ng-modal-overlay''></div><div class=''ng-modal-dialog'' ng-style=''dialogStyle''><div class=''ng-modal-dialog-content'' ng-transclude></div></div></div>'
        }
    });
  angular.module('app', ['common'])

$scope.radioVal = "nothing changes me";

 $scope.myModel={radioVal : "nothing changes me"};

<input  ng-model="myModel.radioVal">

<modal-dialog show="showModal" action="actionFun" value="radioVal">

scope: {
            show: '=',
            action: '&',
            radioVal: '='
       },