HarmonyOS 列表数据刷新，能够实现item的局部刷新吗

item的@State和@Observed的使用，父组件和@Entry中调用的组件建立双向连接，去实现这个功能，这样就可以实现数据的局部刷新了。

示例参考如下：

@Component
struct Child {
  @Link items: TestList[];

  build() {
    Column() {
      ForEach(this.items, (item: TestList) => {
        ChildChild({ item: item });
      })
      Button(`Button: push`).onClick(() => {
        this.items[0].index1 = 3;
        this.items[0].str = 'Third';
      })
    }
  }
}

@Component
struct ChildChild {
  @State item: TestList = new TestList();

  build() {
    Column() {
      Text(`${this.item.index1}+'-----'${this.item.str}`)
    }
  }
}

@Entry
@Component
struct Parent {
  @State arr: TestList[] = [];

  aboutToAppear() {
    let test1: TestList = new TestList();
    test1.index1 = 1;
    test1.str = 'First';
    this.arr.push(test1)
    let test2: TestList = new TestList();
    test2.index1 = 2;
    test2.str = 'Second';
    this.arr.push(test2)
  }

  build() {
    Column() {
      Child({ items: this.arr })
      Button(`Button: push`).onClick(() => {
        this.arr[1].index1 = 4;
        this.arr[1].str = 'Fourth';
      })
    }
  }
}

@Observed
class TestList {
  index1: number = 0;
  str: string = '';
}