檢索在紙面元件下拉列表中選擇的項目

Question

我有以下代碼以下在https://github.com/dart-lang/polymer-core-and-paper-examples/blob/master/web/paper_dropdown.html和EDITED

例子https://github.com/dart-lang/polymer-core-and-paper-examples/blob/master/web/paper_dropdown.dart

的.html

<paper-dropdown-menu 
    label='Click to select..' 
    on-core-select='{{onCoreSelectCountryHandler}}'> 
    <paper-dropdown class='dropdown'> 
    <core-menu id='country' class='menu'> 
     <template repeat='{{country in countries}}'> 
     <paper-item>{{country.name}}</paper-item> 
     </template> 
    </core-menu> 
    </paper-dropdown> 
</paper-dropdown-menu> 

.dart

final List<Country> countries = [ 
    const Country('Afghanistan', 'AF'), 
    const Country('Åland Islands', 'AX')]; 

class Country { 
    final String name; 
    final String code; 
    const Country(this.name, this.code); 
} 

void onCoreSelectCountryHandler(dom.CustomEvent e, var detail) { 
    var detail = new JsObject.fromBrowserObject(e)['detail']; 

    if (detail['isSelected']) { 
    // DOES NOT WORK - HOW DO I GET THE SELECTION ATTEMPTED BELOW 
    // The detail should be related to the Country class but 
    // I can't seem to relate it so I could get the selection. 
    var kuntry = (detail['item'] as PaperItem).text; 

} 

如何使用dart代碼檢索下拉（通常顯示）中的選定元素？

Answer 1

更新

我覺得這是最簡單的方法

void onCoreSelectCountryHandler(dom.CustomEvent e, var detail) { 
    print(countries[$['country'].selected].name); 
    // or if you really need to access the `<paper-item>` element 
    print(detail['item'].text); 
} 

老

有一個在paper-dropdown沒有selected。在paper-dropdown之內包含core-menu，其提供selected。

看到
- https://www.polymer-project.org/0.5/docs/elements/core-menu.html和例如在https://www.polymer-project.org/0.5/docs/elements/paper-dropdown-menu.html

Answer 2

簡單使國家名單觀察到的

final List<Country> cuntries = toObservable[ 
    const Country('Afghanistan', 'AF'), 
    const Country('Åland Islands', 'AX')}] 

選擇被檢索。

我的疏忽。