输入和输出在angular2

Question

我创建一个angular2应用程序。我有一个子组件（MountainListComponent），它由包含在父组件中的其他组件组成（但这不重要）。 在子组件中我有一个山脉列表（<my-mountain class="col-md-4" *ngFor="#mountain of mountains" [mountain]="mountain" (click)="onChange()"></my-mountain>），当我点击山峰时，我想将一个布尔变量（hidelist）传递给父组件。

这两个组件的代码如下。 我已经删除了样板代码。

父组件：

import {Component, Input} from "angular2/core"; 
import {MountainListComponent} from "./mountain-list.component"; 

@Component({ 
    selector: 'my-mountains', 
    template: `hidelist value: {{hidelist}} 
     <div class="row spacing" (childChanged)="hidelist=$event" *ngIf="!hidelist"> 
      <my-mountain-list></my-mountain-list> 
     </div> 
    ` 
}) 

export class MountainsComponent { 
    hidelist = false; 
} 

子组件：

import {Component, Output, EventEmitter} from "angular2/core"; 
import {MountainComponent} from "./mountain.component"; 
import {Mountain} from "./mountain"; 

@Component({ 
    selector: 'my-mountain-list', 
    template: ` 
     <section class="col-md-12"> 
      <my-mountain class="col-md-4" *ngFor="#mountain of mountains" [mountain]="mountain" (click)="onChange()"></my-mountain>  
     </section> 
    `, 
    directives: [MountainComponent], 
    outputs: ['childChanged'] 
}) 

export class MountainListComponent implements OnInit { 
    childChanged = new EventEmitter<boolean>(); 

    onChange() { 
     var hidelist: boolean; 
     hidelist = true; 
     this.childChanged.emit(hidelist); 
    } 
} 

的问题是，hidelist变量值始终为false

Answer 1

添加模板变量#mountain比你可以参考该组件在表达式中：

<my-mountain class="col-md-4" 
    *ngFor="#mountain of mountains" [mountain]="mountain" 
    #mountain 
    (click)="onChange(mountain.hidelist)"></my-mountain> 

Answer 2

将自定义事件绑定从div移至<my-mountain-list>组件，如下所示。

<my-mountain-list (childChanged)="hidelist=$event"></my-mountain-list>

我已经更新父组件： -

import {Component, Input} from "angular2/core"; 
import {MountainListComponent} from "./mountain-list.component"; 

@Component({ 
    selector: 'my-mountains', 
    template: `hidelist value: {{hidelist}} 
     <div class="row spacing" *ngIf="!hidelist"> 
      <my-mountain-list (childChanged)="hidelist=$event"></my-mountain-list> 
     </div> 
    ` 
}) 

export class MountainsComponent { 
    hidelist = false; 
}