Angular 2找不到名称SimpleChanges

M.T*_*M.T 2 timer typescript angular

编译代码时,我收到此错误:找不到名称SimpleChanges.我是Angular 2的新手,你能帮我找到错误的位置吗?这是我的家.

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);
  };



}
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ran*_*al9 19

你忘了从中导入SimpleChanges界面@angular/core.

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