HarmonyOS 鸿蒙Next 多重嵌套的模型属性监听

class ClassA {
  a: number;
  b: ClassB;
  constructor(a: number) {
    this.a = a;
    this.b = new ClassB(a + 2, 2 * a);}
  getA(): number {return this.a; }
  setA(a: number): void {this.a = a;}}
@Observed
class ClassC {
  c: number;
  constructor(c: number) {this.c = c;}
  getC(): number {return this.c;}
  setC(c: number): void {this.c = c; }}
@Observed
class ClassB {
  b: number = 47;
  c: ClassC;
  constructor(b: number, c: number) {
    this.b = b;
    this.c = new ClassC(c);}
  getB(): number {
    return this.b; }
  setB(b: number): void {
    this.b = b;}
  getC(): number {
    return this.c.getC();}
  setC(c: number): void {
    return this.c.setC(c);
  }}
@Component
struct ViewClassB {
  @ObjectLink b: ClassB;
  build() {
    Column({ space: 10 }) {
      Text(`b: ${this.b.getB()}`)
      Button("5 Change B")
        .onClick(() => {
          this.b.setB(this.b.getB() + 1);
        })}}}
@Component
struct ViewClassC {
  @ObjectLink c: ClassC;
  build() {
    Column({ space: 10 }) {
      Text(`c: ${this.c.getC()}`)
      Button("4 Change C")
        .onClick(() => {
          this.c.setC(this.c.getC() + 1);
        }) }}}
@Entry
@Component
struct MyView {
  // 对象包含关系：A对象(B对象(C对象))
  @State a: ClassA = new ClassA(10); //10,12,20
  build() {
    Column({ space: 10 }) {
      Text(`c: ${this.a.b.c.c}`)
      Button("1 Change ClassC.c")
        .onClick(() => {
          this.a.b.c.c += 1;
        })
      Text(`b: ${this.a.b.b}`)
      Button("2 Change ClassB.b")
        .onClick(() => {
          this.a.b.b += 1;
        })
      // 改变A对象下a属性时可以触发@State A对象数据刷新，因此会出现先按了4，5按钮后123上数据由于处于对象内对象无法更新，点击了3触发@StateA对象内部数据变更会触发对象数据刷新
      Text(`b: ${this.a.a}`)
      Button("3 Change ClassA.a")
        .onClick(() => {
          this.a.a += 1;
        })
      //A对象下B对象，C对象均建议使用子组件+[@ObjectLink](/user/ObjectLink)来使用
      ViewClassC({ c: this.a.b.c }) // Text(`c: ${this.b.c.c}`)的替代写法
   ViewClassB({ b: this.a.b })   }}}