启用 Http 服务
- 打开AppModule
- 从 @angular/common/http导入HttpClientModule
- 添加到 @NgModule 的 imports数组
            
            
              typescript
              
              
            
          
          // app.module.ts:
 
import {NgModule} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
 
// 导入 HttpClientModule
import {HttpClientModule} from '@angular/common/http';
 
@NgModule({
  imports: [
    BrowserModule,
    // 'imports' 添加 HttpClientModule 模块
    HttpClientModule,
  ],
})
export class MyAppModule {}发起一个 get 请求
            
            
              typescript
              
              
            
          
          @Component(...)
export class MyComponent implements OnInit {
 
  results: string[];
 
  // 将HttpClient注入到组件或服务中
  constructor(private http: HttpClient) {}
 
  ngOnInit(): void {
    // 发起 HTTP 请求
    this.http.get('/api/items').subscribe(data => {
      // 从JSON响应中读取结果字段
      this.results = data['results'];
    });
  }
}错误处理
            
            
              typescript
              
              
            
          
          http
  .get('/api/items')
  .subscribe(
    // Successful responses call the first callback.
    data => {...},
    // Errors will call this callback instead:
    err => {
      console.log('Something went wrong!');	
    }
  );