Angular 2 - Can't resolve all parameters for component: (?)

Question

I started an Angular2 app and I have an issue since days !

Can\'t resolve all parameters for HomeComponent: (?).(…) 

But my issue is not a

Answer 1

Import this

import {Inject} from '@angular/core';

And change your constructor to

constructor(@Inject(AuthService) _authService: AuthService) 
{

}

you should @Inject any service into constructor before using it.

and your service should be injectable

@Injectable()
export class AuthService {

}