Ng2 通过服务在组件之间共享数据

Question

执行完每个步骤后，我仍然面临同样的问题。

Angular2 data Sharing

仍然无法通过共享服务在组件之间共享数据。

我的工作流程：通过登录服务登录后，我想将 UserDetails 响应分享到关于页面。

我只在@NgModule 中的app.module.ts 中作为提供者注入了登录服务

===登录组件=====

import { Component } from '@angular/core';
import { Http } from '@angular/http';
import { UserAccount } from '../model/userAccount.interface';
import { LoginService } from './login.service';
import { Router } from '@angular/router';

@Component({
selector: 'app-login',
templateUrl: './login.component.html',
})

export class LoginComponent  { 

emailAddress : string;
password : string;
submitted : boolean;
errorMessage : string;

constructor(private loginService: LoginService, private router : Router) {
    this.submitted = false;
}

login() {
    // event.preventDefault();
    this.submitted = true;
    this.loginService.getLogin(this.emailAddress, this.password).subscribe(
        u => this.router.navigate(['/about']),
        error =>  this.errorMessage = <any>error);
}

}

===登录服务====

@Injectable()
export class LoginService {
   private userAccount : UserAccount[];

  constructor (private http: Http) {}

getLogin(): Observable<UserAccount[]> {
  return this.http.get(this.url)
                .map(this.extractData);
}

private extractData(res: Response) {
  let body = res.json();
  this.userAccount = body.data.user[0]
  return this.userAccount || { };
}

 getUserDetails() {
  return this.userAccount;
}
}

======关于组件=====

export class AboutComponent implements OnInit{

// initialize a private variable _data, it's a BehaviorSubject
// private _data = new BehaviorSubject<UserAccount[]>([]);
userDetails : UserAccount[];
lService : LoginService;

constructor(loginService: LoginService) {
    this.lService = loginService;
    this.userDetails = this.lService.getUserDetails();
    console.log(this.userDetails);
}

ngOnInit() {

}
}

Answer 1

更改.map(this.extractData);

到

.map((res)=>this.extractData(res));

或.map(this.extractData.bind(this));

您的 this 没有在第一个函数的 map 函数中引用您的组件。