如何在 Visual Studio 中使用默认 angular 项目导入组件

Question

I am having a problem with angular using the default angular visual studio project. I am currently unsure of how to add more than one component to a.ts file and I am starting very simple

all i am trying to do is add the existing "Counter" component to the existing fetch-data.html page

import { Component } from '@angular/core';

@Component({
  selector: 'app-counter-component',
  templateUrl: './counter.component.html'
})

export class CounterComponent {
    public currentCount = 0;

    public incrementCounter() {
      this.currentCount++;
    }
}

to fetch-data-component.html

<h1 id="tableLabel">Weather forecast</h1>

<p>This component demonstrates fetching data from the server.</p>
<h1>Counter</h1>

<p>This is a simple example of an Angular component.</p>

<p aria-live="polite">Current count: <strong>{{ counter }}</strong></p>

<button class="btn btn-primary" (click)="counter.incrementCounter()">Increment</button>

<p *ngIf="!forecasts"><em>Loading...</em></p>

<table class='table table-striped' aria-labelledby="tableLabel" *ngIf="forecasts">
  <thead>
    <tr>
      <th>Date</th>
      <th>Temp. (C)</th>
      <th>Temp. (F)</th>
      <th>Summary</th>
    </tr>
  </thead>
  <tbody>
    <tr *ngFor="let forecast of forecasts">
      <td>{{ forecast.date }}</td>
      <td>{{ forecast.temperatureC }}</td>
      <td>{{ forecast.temperatureF }}</td>
      <td>{{ forecast.summary }}</td>
    </tr>
  </tbody>
</table>

import { Component, Inject } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { CounterComponent } from '../counter/counter.component';

@Component({
    selector: 'app-fetch-data',
    templateUrl: './fetch-data.component.html',
})

export class FetchDataComponent
{
  public counter: CounterComponent;
  public forecasts: WeatherForecast[];

    constructor(http: HttpClient, @Inject('BASE_URL') baseUrl: string)
    {
      http.get<WeatherForecast[]>(baseUrl + 'weatherforecast').subscribe(result =>
      {
          this.forecasts = result;
      }, error => console.error(error));
  }
}

interface WeatherForecast {
  date: string;
  temperatureC: number;
  temperatureF: number;
  summary: string;
}

as you can see I have imported CounterComponent and added it to the export class

export class FetchDataComponent
{
  public counter: CounterComponent;

but all I get is errors."incrementCounter is not a function" I am not really sure where to go after importing CounterComponent

how can I import and add the counter component to the fetch-data.html page? What is the right way to import and use this component

Answer 1

1. Make sure that both components are in a modules declarations array.
2. Your FetchDataComponent gonna be a parent component, CounterComponent gonna be it's child, meaning that it will be inside the parents template, that way they can interact with each other and share data.
3. CounterComponent has a selector app-counter-component. Place it in a FetchDataComponent template like so <app-counter-component></app-counter-component>

---

fetch-data.component.html

<h1> Some heading</h1>
<app-counter-component></app-counter-component>
<h2> The End </h2>

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