HarmonyOS 大数字无法利用@state实时渲染

// xxx.ets
import { Decimal } from '@kit.ArkTS';
@Entry
@Component
struct ViewB {
  @State bag: Decimal = new Decimal(5);
  @State big: bigint = BigInt(52);
  build() {
    Column() {
      Text(this.bag.toString())
      Text(this.big.toString())
      Button(变更数字)
      .width(320)
        .backgroundColor('#ff7fcf58')
        .margin(10)
        .onClick(() => {
          this.bag = new Decimal(20);
          this.big = BigInt(99)
        })
    }
  }
}