从@ngModule调用一个服务

Question

我想从登录组件中调用@ngModule中导入的服务。我就是这么做的，但不管用。我刚刚开始做A2的最终版本。

export class Login implements OnInit{
  constructor(
    private _service: Service
    ) {
  }
  ngOnInit() {
    this._service.login(value)
        .subscribe(x => console.log(x));
    }
  }
}

我@ngModule

import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import { LoginService } from '../service/login.service'; 
import { Login } from './login.component';
export const routes = [
  { path: '', component: Login, pathMatch: 'full' }
];
@NgModule({
  declarations: [
    Login
  ],
  imports: [
    CommonModule,
    RouterModule.forChild(routes)
  ],
  providers: [LoginService]
})
export default class LoginModule {
  static routes = routes;
}

有什么想法吗?

Answer 1

内部构造函数Service应该是LoginService，因为您想要访问/创建LoginService的实例。还要确保LoginService已导入。

constructor(
   private _service: LoginService //<-- changed dependency type name
   ) {
}

Answer 2

将组件类改为使用LoginService

export class Login implements OnInit{
  constructor(
    private _service: LoginService
    ) {
  }
  ngOnInit() {
    this._service.login(value)
        .subscribe(x => console.log(x));
    }
  }
}

Answer 3

你还必须在Login组件中导入LoginService，并将其添加到构造函数中:

constructor( _service: LoginService) {  }