HarmonyOS TabContent与父界面的变量传递

tabcontent目前不支持预加载，但是@Prop修饰的变脸仍可以接收到传递的参数；因此可以在业务上做出一些兼容，比如在aboutToAppear或onAppear内处理一些初始化的动作，或者可以换用其他组件替代tab实现效果。

这里用swiper替代实现了效果，可以参考一下：

@Entry
@Component
struct SwiperExample {
  private swiperController: SwiperController = new SwiperController()
  private data = [0,1,2,3,4,5,6]
  @State currentIndex: number = 0
  build() {
    Column() {
      Swiper(this.swiperController) {
        ForEach(this.data, (item: string,index) => {
          FreezeChild({ message: this.currentIndex, index: index }).onAppear(()=>{
            console.info("初始化外部组件:",item)
          })
        }, (item: string) => item)
      }
      .layoutWeight(1)
      .cachedCount(2)
      .index($$this.currentIndex)
      .indicator(false)
      .loop(true)
      .duration(300)
      .curve(Curve.Linear)
      Row({ space: 12 }) {
        Text(`当前在第${this.currentIndex+1}页,总计${this.data.length}`)
      }.margin(5)
    }.width('100%')
    .margin({ top: 5 })
  }
}
@Component
struct FreezeChild {
  @Link @Watch("onMessageUpdated") message: number
  private index: number = 0
  onMessageUpdated() {
    console.info(`触发tabcontent内监听回调 ${this.message}, index: ${this.index}`)
  }
  build() {
    Text("内容" + `${this.message}, index: ${this.index}`)
      .fontSize(50)
      .fontWeight(FontWeight.Bold)
  }
}