发出事件时，Angular 2调用函数/方法 [英] Angular 2 call a function/method when an event is emitted

问题描述

我有一个组件，单击关闭按钮后可以从页面中删除它.我公开了一个 testClose 事件，当组件关闭时，用户可以注册该事件以执行某些工作.关闭组件后，如何注册该事件以调用函数?例如，当TestComponent关闭时，我想将closeCounter递增1.这是plnkr:

I have a component which can be removed from the page when a close button is clicked. I have exposed a testClose event that a user can register to do some work when the component is closed. How do I register to that event to call a function when the component is closed? For example, I would like to increment the closeCounter by 1 when the TestComponent is closed. Here is the plnkr:

https://plnkr.co/edit/iGyzIkUQOTCGwaDqr8o0?p=preview

暴露事件的TestComponent:

TestComponent which exposes an event:

import {Component, Input, Output, EventEmitter} from 'angular2/core';

@Component({
  selector: 'test',
  template: `
      <div class="box" *ngIf="!_close">
        <button class="close" (click)="close()">x</button>
      </div>
    `,
    styles:[
      `
        .box{
          background: yellow;
          height: 100px;
          width: 100px;
        }
      ` 
    ]
})
export class TestComponent{

  @Input("testClose") _close = false;
  @Output("testCloseChange") _closeChange = new EventEmitter<boolean>(false);

  close(): void{
    this._close = true;
    this._closeChange.emit(true);
  }

  open(): void{
    this._close = false;
    this._closeChange.emit(true);
  }

}

应注册到TestComponent的close事件以调用某些功能的应用程序组件.

App Component which should register to the close event of the TestComponent to call some function.

import {Component} from 'angular2/core';
import {TestComponent} from './test.component';

@Component({
    selector: "my-app",
    template: `
      <div class="container">
        <test [testClose]="isClose"></test>
        Close Count: {{closeCount}}
      </div>
    `,
    directives: [TestComponent]
})
export class AppComponent{

  isClose: boolean = false;
  closeCount: number = 0;

  incrementClose(): void{
    this.closeCount++;
  }

}

推荐答案

只需向正在发出的事件添加一个侦听器

Just add a listener to the event being emitted

(testCloseChange)="onTestCloseChange($event)"

因此，应用程序组件模板将如下所示

So app component template will look like this

<div class="container">
   <test [testClose]="isClose" (testCloseChange)="onTestCloseChange($event)"></test>
   Close Count: {{closeCount}}
</div>

在App组件类中，您应该定义onTestCloseChange

And inside the App component class you should define the onTestCloseChange

export class AppComponent{

  onTestCloseChange(event) {

  }

}

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