Angular 2 找不到名称 SimpleChanges

Question

编译代码时出现此错误:找不到名称 SimpleChanges。我是 Angular 2 的新手，您能帮我找出错误所在吗？这是我的 home.ts:

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

import { NavController } from 'ionic-angular';
import {Observable} from 'rxjs/Rx';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  date: Date;
  constructor(public navCtrl: NavController) {
    this.date = new Date();
  }


  ticks = 0;
  ngOnChanges(changes: {[propertyName: string]: SimpleChanges}){
    if(changes['ticks']){
        if(this.ticks == 20)
            this.ticks = 0;
    }
  }
  ngOnInit(){
    let timer = Observable.timer(0,1000);
    timer.subscribe(t=>this.ticks = t);
  };



}

Answer 1

您忘记从 @angular/core 导入 SimpleChanges 接口(interface)。

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