選擇第二個框的觸發事件，Angular

Question

我有2個框，第一個選擇父項，第二個選擇所選父項的子項。

如何在第二次選擇後運行波紋管功能？

角功能

$scope.myFunc = function() { 
      var jsonItem = JSON.parse($scope.formData.formatType.id); 
      sessionStorage.setItem('format', jsonItem); 
     } 

HTML

<select ng-model="formData.ProductType.name" ng-change="productTypeChange()" ng-options="product.name as product.name for product in productsandformats"> 
    <option value="">- Please Choose -</option> 
</select> 

<select ng-model="formData.formatType" ng-options="format.Fname for format in formats.format" ng-if="formData.ProductType.name"> 
    <option value="">- Please Choose -</option> 
</select> 

Answer 1

使用ng-change

<select ng-model="formData.formatType" 
      ng-options="format.Fname for format in formats.format" 
      ng-if="formData.ProductType.name" ng-change="myFunc()"> 
     <option value="">- Please Choose -</option> 
    </select>`