TypeScript Http请求

1、ts 文件

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

@Component({
  selector: 'app-fetch-data',
  templateUrl: './fetch-data.component.html'
})
export class FetchDataComponent {
  public forecasts: WeatherForecast[];

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

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

2、html 文件

<h1>Weather forecast</h1>

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

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

<table class='table' *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.dateFormatted }}</td>
      <td>{{ forecast.temperatureC }}</td>
      <td>{{ forecast.temperatureF }}</td>
      <td>{{ forecast.summary }}</td>
    </tr>
  </tbody>
</table>