Angular2模板解析错误：属性绑定ng对于嵌入式模板上的任何指令都不使用

这是Angular2模板：

<paper-dropdown-menu label="Country">
        <paper-listbox class="dropdown-content" [(ngModel)]="selectedCountry" (ngModelChange)="GetAdmin1s($event)">
            <paper-item *ngFor="let country of countries" value="{{country.Id}}">{{country.Name}}</paper-item>
        </paper-listbox>
    </paper-dropdown-menu>

我收到此错误：

"Template parse errors:
Property binding ngFor not used by any directive on an embedded template (""dropdown-content" [(ngModel)]="selectedCountry" (ngModelChange)="GetAdmin1s($event)">
            [ERROR ->]<paper-item *ngFor="let country of countries" value="{{country.Id}}">{{country.Name}}</paper-item>
 "): LocationComponent@4:12
Property binding ngForCountry not used by any directive on an embedded template (""dropdown-content" [(ngModel)]="selectedCountry" (ngModelChange)="GetAdmin1s($event)">
            [ERROR ->]<paper-item *ngFor="let country of countries" value="{{country.Id}}">{{country.Name}}</paper-item>
 "): LocationComponent@4:12"

国家变量定义为：

public countries: Array<Country> = [];

我使用ngFor有什么问题？为什么要寻找ngForCountry？

解决方法

试试可能有帮助

<paper-dropdown-menu label="Country">
    <paper-listbox class="dropdown-content" [(ngModel)]="selectedCountry" (ngModelChange)="GetAdmin1s($event)">
        <paper-item ngFor #country [ngForOf]="countries" value="{{country.Id}}">{{country.Name}}</paper-item>
    </paper-listbox>
  </paper-dropdown-menu>