Angular 4-找不到名称"HttpClient" [英] Angular 4 - Cannot find name 'HttpClient'

问题描述

我正在尝试访问JSON供稿，但是在文档中进行了更改之后>我收到以下错误

I'm trying to access a JSON feed but after making the changes from the documentation I get the following error

找不到名称'HttpClient'"

"Cannot find name 'HttpClient'"

我已经看过本教程几次，但我一直在努力寻找为什么会出现此错误的原因.

I've looked over the tutorial a few times but I'm struggling to find why I get this error.

我执行Http请求的组件.

My component where I perform the Http request.

rooms.parent.component.ts

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

@Component({
 /.../
})

export class RoomParentComponent implements OnInit {
  results: string[];

  // Inject HttpClient into your component or service.
  constructor(private http: HttpClient) {}

  ngOnInit(): void {
    // Make the HTTP request:
    this.http.get(/.../).subscribe(data => {
      this.results = data;
    });
  }
}

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import {HttpClientModule} from '@angular/common/http';
import { AppComponent } from './app.component';
import { RoomParentComponent } from './rooms.parent.component';

@NgModule({
  declarations: [
    AppComponent,
    RoomParentComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
  ],
  providers: [],
  bootstrap: [AppComponent]
})

export class AppModule { }

如何解决以上错误并将HttpClient注入到构造函数中?

How do I resolve the above error and inject the HttpClient into the constructor?

我的Angular版本是4.3.2

My Angular version is 4.3.2

推荐答案

HttpClient在Angular 4.3.0版本中引入.另外，您还必须确保已导入&在主AppModule的imports元数据中注入了HttpClientModule.

HttpClient got introduced in Angular 4.3.0 version. Also you have to make sure you have imported & injected HttpClientModule in your main AppModule's imports metadata.

// Import HttpClientModule from @angular/common/http in AppModule
import {HttpClientModule} from '@angular/common/http';


//in place where you wanted to use `HttpClient`
import { HttpClient } from '@angular/common/http';

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