Angular 2依赖项注入不适用于服务

Question

我正在尝试从Angular 2中的UserService获取静态数据。从文档看一切正常，但由于某种原因它无法正常工作。

这是我的UserComponent.ts

import {Component ,OnInit } from '@angular/core';
import {UsersService} from './users.service';


    @Component({
      selector: 'users',
      template: `<h3>Users </h3>
      <ul> 
        <li *ngFor="let user of users">{{user}}</li>
      </ul>
       `,
      providers:[UsersService]
    })
    export class UsersComponent {
        users;
        title;

        construct( usersService: UsersService){
           this.users=usersService.getUsers();
// i also tried this but no luck. this.users = this.usersService.getUsers();
        }

    }

这是我的UsersService.ts

import { Injectable } from '@angular/core';
@Injectable()
export class UsersService {
    users =['krishna','ravi','ram','ramesh','sita'];
          getUsers()  {
            return this.users ;
        }

}

如预期的那样，其输出应为

<h3>Users </h3>
  <ul>  
    <li>Krishna</li>
    <li>Ravi</li>
    <li>Hari</li>
    <li>etc</li>
  </ul>

但它不会在* ngFor循环上重复。 我也打印了{{users}}，它返回了空白。 请建议我这里的问题是什么。

Answer 1

constructor存在拼写错误

export class UsersComponent {
  users;
  title;

  constructor( private usersService: UsersService) {        
  }

  ngOnInit() {
    this.users = this.usersService.getUsers();
  }
}