HarmonyOS 鸿蒙Next @watch 怎么监听 @Trace

参考如下方式是否可行：

let nextId: number = 0;
@ObservedV2
class Person {
@Trace age: number = 0;
constructor(age: number) {
this.age = age;
}
}
@ObservedV2
class Info {
id: number = 0;
@Trace personList: Person[] = [];
constructor() {
this.id = nextId++;
this.personList = [new Person(0), new Person(1), new Person(2)];
}
}
@Entry
@Component
struct Page_demo003 {
info: Info = new Info();
@State @Watch(“test”) age: number = 0
test(){
console.info("info age = " + this.age)
}
build() {
Column() {
Text(length: ${<span class="hljs-keyword">this</span>.info.personList.length})
.fontSize(40)
Divider()
if (this.info.personList.length >= 3) {
Text(${<span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">0</span>].age})
.fontSize(40)
.onClick(() => {
this.info.personList[0].age++;
this.age = this.info.personList[0].age
})
    Text(`${<span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">1</span>].age}`)
      .fontSize(<span class="hljs-number">40</span>)
      .onClick(() =&gt; {
        <span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">1</span>].age++;
        <span class="hljs-keyword">this</span>.age = <span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">1</span>].age
      })

    Text(`${<span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">2</span>].age}`)
      .fontSize(<span class="hljs-number">40</span>)
      .onClick(() =&gt; {
        <span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">2</span>].age++;
        <span class="hljs-keyword">this</span>.age = <span class="hljs-keyword">this</span>.info.personList[<span class="hljs-number">2</span>].age
      })
  }

  Divider()

  ForEach(<span class="hljs-keyword">this</span>.info.personList, (item: Person, index: number) =&gt; {
    Text(`${index} ${item.age}`)
      .fontSize(<span class="hljs-number">40</span>)
  })
}
}
}