javascript - 当将服务注入(inject)(导入)到我的构造函数中时，出现 "No provider"错误

Question

Angular 2 - 当将服务注入(inject)(导入)到我的构造函数中时，我收到“无提供程序”错误。

这是我要导入的服务:

 export class EnvironmentService {

   public baseurl: string = "/baseurl/example/";  

 }

这是我的类(class)，出现错误:

import {Http, Headers} from "angular2/http";
import {Injectable} from 'angular2/angular2';
import {EnvironmentService} from './environmentService';

@Injectable()

export class AuthService {

    constructor(private _environmentService: EnvironmentService) {

        //This is where the error is.
        console.log(this._environmentService);

    }

    isUserLoggedIn = (): Promise<boolean> => {   

        return new Promise((resolve, reject) => {
           resolve(true);
        })
    }

}

Answer 1

在app.module.ts中添加AuthServiceProviders