Angular 4 错误:没有 HttpClient 的提供者 [英] Angular 4 Error: No provider for HttpClient

问题描述

我正在使用 CLI 启动一个新的 Angular 项目，但遇到了一个没有提供程序的 HttpClient 错误.

I am starting a new angular project with the CLI and am running into a no provider for HttpClient error.

我已将 HttpClientModule 添加到我的模块导入中，这似乎是这种情况下的常见罪魁祸首.除此之外没有在网上找到很多，所以我不确定问题可能是什么.

I have added HttpClientModule to my module imports which seems to be the usual culprit in this scenario. Not finding a lot online other than that so I am not sure what the issue may be.

我的 app.module.ts

my app.module.ts

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

和我的服务

@Injectable()
export class FlexSearchService {


    constructor(private http: HttpClient) {}

    getSavedSearchResult(index: string, queryName: string, query: string ): Observable<any> {
      const url = `${environment.flexUrl}/${index}/search`;
      const item = new SearchQuery({queryName: queryName, variables: {q: query}});
      return this.http.post(url, item);
    }
}

和 ng 版本给出以下输出

and ng version gives the following output

@angular/cli: 1.4.2
node: 6.9.4
os: darwin x64
@angular/animations: 4.4.4
@angular/common: 4.4.4
@angular/compiler: 4.4.4
@angular/core: 4.4.4
@angular/forms: 4.4.4
@angular/http: 4.4.4
@angular/platform-browser: 4.4.4
@angular/platform-browser-dynamic: 4.4.4
@angular/router: 4.4.4
@angular/cli: 1.4.2
@angular/compiler-cli: 4.4.4
@angular/language-service: 4.4.4
typescript: 2.3.4

我的 tsconfig

my tsconfig

{
  "compileOnSave": false,
  "compilerOptions": {
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es5",
    "typeRoots": [
      "node_modules/@types"
    ],
    "lib": [
      "es2017",
      "dom"
    ]
  }
}

我的测试

import { TestBed, inject } from '@angular/core/testing';
import { HttpClientModule } from '@angular/common/http';
import { FlexSearchService } from './flex-search.service';

describe('FlexSearchService', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [FlexSearchService, HttpClientModule]
    });
  });
  it('should be created', inject([FlexSearchService], (service: FlexSearchService) => {
    expect(service).toBeTruthy();
  }));

非常感谢任何帮助！

推荐答案

在你的测试中

TestBed.configureTestingModule({
      providers: [FlexSearchService, HttpClientModule]
    });

应该是

TestBed.configureTestingModule({
      imports: [HttpClientModule],
      providers: [FlexSearchService]
    });

甚至更好(如果你想模拟请求):

or even better (if you want to mock request):

TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [FlexSearchService]
    });

这篇关于Angular 4 错误:没有 HttpClient 的提供者的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！