订阅Angular 2

Question

我的应用上有一个时钟，它使用observable每秒更新一次：

clock.service：

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

import {Observable} from 'rxjs/observable';

@Injectable()
export class ClockService {

  mydate: Date;

  constructor() {}

  getClock(): Observable<any> {
    return new Observable(observer => {
      setInterval(()=>{
        this.mydate = new Date();
        observer.next(this.mydate);

      }, 1000);
    });
  }

}

header.component：

...
private mydate: Date;

...
constructor(private clockService: ClockService, private alertService: AlertsService) { }

  ngOnInit() {
    this.mydate = this.clockService.getClock().subscribe(res => this.mydate = res);;
  }

我收到一个错误： error TS2322: Type 'Subscription' is not assignable to type 'Date'. Property 'toDateString' is missing in type 'Subscription'

Answer 1

ngOnInit() {
    this.mydate = this.clockService.getClock().subscribe(res => this.mydate = res);;
  }

这是错误的。正如错误所述，您将subscription绑定到Date。 改为：

ngOnInit() {
    this.clockService.getClock().subscribe(res => this.mydate = res);;
  }