1.子调用父的方法

子组件

父组件

2.使用emitter实现孙子传爷

孙子组件

import emitter from '@ohos.events.emitter';

    let event: emitter.InnerEvent = {
              eventId: 1,
              priority: emitter.EventPriority.HIGH
            };

            let eventData: emitter.EventData = {
              data: {
                "state": true,
                "item": JSON.stringify(this.item)
              }
            };

            // 孙子组件发送事件
            emitter.emit(event, eventData);

 爷爷组件

  aboutToAppear(): void {
   

    let event: emitter.InnerEvent = {
      eventId: 1
    };

    let callback = (eventData: emitter.EventData): void => {
      if (eventData && eventData.data) {

        this.item = JSON.parse(eventData.data.item)
        this.isShow = eventData.data.state
      }
    };

    // 爷爷组件监听事件
    emitter.on(event, callback);
  }

3.@Observed和@ObjectLink应用

@Observed
class Person {
  age: number = 18
  son: Son = new Son()
}

@Observed
class Son {
  weight: number = 300
}

@Component
struct MyButton {
  @ObjectLink
  son: Son

  build() {
    Column() {
      Button('son的weight' + this.son.weight)
        .onClick(() => {
          // this.son.weight++
        })

    }

  }
}

@Entry
@Component
struct Index {
  @State
  person: Person = new Person()

  build() {
    Column() {
      MyButton({
        son: this.person.son
      }).onClick(() => {
        // this.person.son.weight++
      })
      Button('Personde age' + this.person.age)
        .onClick(() => {
          this.person.age++
        })
    }

  }
}