angular4-注入服务

//配置已创建的服务:
import { MemberService } from "./member.service";
@NgModule({
  // ...
  providers: [MemberService]
})
export class AppModule { }

//导入已创建的服务
import { MemberService } from '../member.service';

//使用构造注入方式，注入服务
export class MembersComponent implements OnInit {
   // ...
   constructor(private memberService: MemberService) { }
}

创建 MemberService 服务

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';

@Injectable()
export class MemberService {
    constructor(private http: Http) { }

    getMembers() {
        return this.http
            .get(`https://api.github.com/orgs/angular/members?page=1&per_page=5`)
            .map(res => res.json())
    }
}

使用 MemberService 服务

import { MemberService } from "./member.service";

@Component({...})
export class MembersComponent implements OnInit {
    members: Member[];

    constructor(private memberService: MemberService) { }

    ngOnInit() {
        this.memberService.getMembers()
            .subscribe(data => {
                if (data) this.members = data;
            });
    }
}