Angular 角度2注入到另一个服务的服务未定义

我正在尝试创建一个小框架，使我更容易实现CRUD功能

因此，我创建了一个BaseHttpService，如下所示：

... <imports> ...
@Injectable()
export class BaseHttpService {
  constructor(
    private http: Http
  ) {
    console.log('ctor');
    this.apiUrl$.subscribe(apiUrl => this.rootApiUrl = apiUrl.removeTrailingSlash());
  }
  public getPagedResultOfType<T extends IBaseEntity>(url: string, vm: ISearchVm<T>, options?: RequestOptions): Observable<PagedResult<T>>{ ... <implementation> ... }
  ... <other methods> ...
}

import { BaseHttpService} from '../servicePath';

这是我目前拥有的，但这不起作用。我得到的错误是：

无法读取未定义的属性“getPagedResultOfType”

---

如何将BaseHttpService注入我的BaseAppsumentyReadOnlyService？

如下导入您的服务：

... <imports> ...
@Injectable()
export class BaseHttpService {
  constructor(
    private http: Http
  ) {
    console.log('ctor');
    this.apiUrl$.subscribe(apiUrl => this.rootApiUrl = apiUrl.removeTrailingSlash());
  }
  public getPagedResultOfType<T extends IBaseEntity>(url: string, vm: ISearchVm<T>, options?: RequestOptions): Observable<PagedResult<T>>{ ... <implementation> ... }
  ... <other methods> ...
}

import { BaseHttpService} from '../servicePath';

然后在构造函数中这样声明它：

constructor(
    private baseHttpService: BaseHttpService
  ) { 
    console.log(this.baseHttpService); 
  }

让我知道它是否像这样工作，如果不是，请复制/粘贴控制台错误：D

编辑1:

@NgModule({
  declarations: [
    myComponent
  ],
  imports: [
    CommonModule,
    HttpModule
  ],
  providers: [
    BaseHttpService,
    BaseAppSumEntityReadOnlyService,
  ]
})
export class AppSumFrameworkModule { }

服务：

BaseHttpService

... <imports> ...
@Injectable()
export class BaseHttpService {
  constructor(
    private http: Http
  ) {
    console.log('ctor');
    this.apiUrl$.subscribe(apiUrl => this.rootApiUrl = apiUrl.removeTrailingSlash());
  }
  public getPagedResultOfType<T extends IBaseEntity>(url: string, vm: ISearchVm<T>, options?: RequestOptions): Observable<PagedResult<T>>{ ... <implementation> ... }
  ... <other methods> ...
}

@Injectable()
export class BaseAppSumEntityReadOnlyService<T extends IBaseEntity>{
  constructor(
    private baseHttpService: BaseHttpService
  ) { 
    console.log('ro ctor');
    console.log(this.baseHttpService); // <-- this is always undefined
  }

  getAll(vm: ISearchVm<T>): Observable<PagedResult<T>>{
    const url = `${this.baseUrl}`;
    console.log(this.baseHttpService);
    return this.baseHttpService.getPagedResultOfType<T>(url, vm); // <-- this fails because baseHttpService is undefined: Cannot read property 'getPagedResultOfType' of undefined
  }
  ... <more methods>
}

... <imports> ...
@Component()
export class myComponent {
 constructor(
    private baseAppService: BaseAppSumEntityReadOnlyService
  ) { 
    console.log(this.baseAppService); 
  }
}

模块：

@NgModule({
  declarations: [
    myComponent
  ],
  imports: [
    CommonModule,
    HttpModule
  ],
  providers: [
    BaseHttpService,
    BaseAppSumEntityReadOnlyService,
  ]
})
export class AppSumFrameworkModule { }

组件：

myComponent

... <imports> ...
@Injectable()
export class BaseHttpService {
  constructor(
    private http: Http
  ) {
    console.log('ctor');
    this.apiUrl$.subscribe(apiUrl => this.rootApiUrl = apiUrl.removeTrailingSlash());
  }
  public getPagedResultOfType<T extends IBaseEntity>(url: string, vm: ISearchVm<T>, options?: RequestOptions): Observable<PagedResult<T>>{ ... <implementation> ... }
  ... <other methods> ...
}

@Injectable()
export class BaseAppSumEntityReadOnlyService<T extends IBaseEntity>{
  constructor(
    private baseHttpService: BaseHttpService
  ) { 
    console.log('ro ctor');
    console.log(this.baseHttpService); // <-- this is always undefined
  }

  getAll(vm: ISearchVm<T>): Observable<PagedResult<T>>{
    const url = `${this.baseUrl}`;
    console.log(this.baseHttpService);
    return this.baseHttpService.getPagedResultOfType<T>(url, vm); // <-- this fails because baseHttpService is undefined: Cannot read property 'getPagedResultOfType' of undefined
  }
  ... <more methods>
}

... <imports> ...
@Component()
export class myComponent {
 constructor(
    private baseAppService: BaseAppSumEntityReadOnlyService
  ) { 
    console.log(this.baseAppService); 
  }
}

。。。
@组件（）
导出类myComponent{
建造师(
专用baseAppService:BaseAppsumentyReadOnlyService
) { 
console.log（this.baseAppService）；
}
}

这是当前的操作方式：从“/base http.service”导入{BaseHttpService}@Injectable（）导出类BaseAppsumentyReadOnlyService{constructor（受保护的baseHttpService:baseHttpService）{console.log（'ro-ctor-'）；console.log（this.baseHttpService）；}}//控制台日志给出：'ro-ctor-'UndeinedChange（在那里为

私有
进行第二次
受保护的
并重新编译应用程序。查看问题是否仍然存在。我会继续调查你的问题，看看能不能找到问题所在is@AppSum在您的示例代码中，我看到这个
@Inject（forwardRef（（）=>BaseHttpService））公共BaseHttpService:BaseHttpService
。您当时使用的是哪个版本？你的OP上的那个还是这条评论上的那个？将其更改为private会得到相同的结果。（为了让您知道为什么，我将其设置为受保护，以便能够在将实现其余CRUD功能并扩展此BaseReadOnlyService的服务中使用它）我使用Angular CLI，因此更改代码和测试不同的内容非常容易。我尝试了forwardRef和专用的baseHttpService:baseHttpService。结果是一样的。