@Watch的使用方法

import { Vue, Component, Watch } from 'vue-property-decorator'
@Component
export default class YourComponent extends Vue {
  @Watch('child')
  onChildChanged(val: string, oldVal: string) {}
  @Watch('person', { immediate: true, deep: true })
  onPersonChanged1(val: Person, oldVal: Person) {}
  @Watch('person')
  onPersonChanged2(val: Person, oldVal: Person) {}
}