HarmonyOS 一个组件怎么监听另一个组件属性改变

// ParentComponent.ets
@Entry
@Component
struct ParentComponent {
    @State private sharedValue: number = 0;

    build() {
        Column({ space: 20 }) {
            ChildComponentA({ value: this.sharedValue, onValueChange: (newVal) => this.sharedValue = newVal })
            ChildComponentB({ observedValue: this.sharedValue })
        }.padding(20)
    }
}

// ChildComponentA.ets
@Component
struct ChildComponentA {
    @Prop value: number;
    @Prop onValueChange: (number) => void;

    build() {
        Column({ space: 20 }) {
            Text(`Current Value: ${this.value}`)
            Button("Increment Value")
                .onClick(() => this.onValueChange(this.value + 1))
        }
    }
}

// ChildComponentB.ets
@Component
struct ChildComponentB {
    @Prop observedValue: number;

    build() {
        Text(`Observed Value: ${this.observedValue}`)
    }
}