如何使用Angular 2中的指令获取旧值和新值？

import { Directive, Input, OnChanges, SimpleChanges } from '@angular/core';

@Directive({
  selector: '[myDirective]'
})
export class MyDirective implements OnChanges {
  @Input() myProperty: any;

  ngOnChanges(changes: SimpleChanges) {
    // 在ngOnChanges方法中可以获取到旧值和新值
    if (changes.myProperty) {
      const oldValue = changes.myProperty.previousValue;
      const newValue = changes.myProperty.currentValue;
      console.log('旧值：', oldValue);
      console.log('新值：', newValue);
    }
  }
}

<div myDirective [myProperty]="myValue"></div>