dart - 如何使用核心菜单选择

Question

我取自http://www.dartdocs.org/documentation/core_elements/0.1.0+1/index.html#core_elements/core_elements-core_menu.CoreMenu以下内容

  <section>
    <core-menu selected="0" on-core-select="{{selectAction}}">
      <core-item icon="settings" label="Settings"></core-item>
      <core-item icon="dialog" label="Dialog"></core-item>
      <core-item icon="search" label="Search"></core-item>
    </core-menu>
  </section>


  void selectAction (e, detail)
  {
    if ( e.target.isSelected)
    {
      var selectedItem = detail.item;

      print ( selectedItem );
    }
  }

即使只是尝试使用代码运行应用程序而没有尝试选择也会给出以下内容

Exception: Class 'CoreMenu' has no instance getter 'isSelected'.

NoSuchMethodError: method not found: 'isSelected'
Receiver: Instance of 'CoreMenu'

这里有错误还是代码错误

Answer 1

我的一个应用程序中的示例

import 'dart:js' as js;

  void menuSelectHandler(dom.CustomEvent e) {
    var detail = new js.JsObject.fromBrowserObject(e)['detail'];
    //var detail = e['detail']; // you can try without js.JsObject.fromBrowserObject(e), but the last time I tried it didn't work for me without it

    if(detail['isSelected']) {
      var item = (detail['item'] as CoreItem);
      selectedMenuLabel = item.label;

    }
  }