HarmonyOS tabs切换生命周期监听？

Question

请问tabs的tabcontent的切换，是否可以在页面中监测到切换的事件呢

Answer 1

可使用onTabBarClick事件，参考文档：

https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/ts-container-tabs-V5

tabs切换触发的应该是子组件组件级的生命周期aboutToAppear

参考一下如下demo，点击切换tab是可以检测到切换的index的

@Entry
@Component
struct TabsExample {
  @State fontColor: string = '#182431'
  @State selectedFontColor: string = '#007DFF'
  @State currentIndex: number = 0
  private controller: TabsController = new TabsController()

  @Builder tabBuilder(index: number, name: string) {
    Column() {
      Text(name)
        .fontColor(this.currentIndex === index ? this.selectedFontColor : this.fontColor)
        .fontSize(16)
        .fontWeight(this.currentIndex === index ? 500 : 400)
        .lineHeight(22)
        .margin({ top: 17, bottom: 7 })
      Divider()
        .strokeWidth(2)
        .color('#007DFF')
        .opacity(this.currentIndex === index ? 1 : 0)
    }.width('100%')
  }

  build() {
    Column() {
      Tabs({ barPosition: BarPosition.Start, index: this.currentIndex, controller: this.controller }) {
        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#00CB87')
        }.tabBar(this.tabBuilder(0, 'green'))

        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#007DFF')
        }.tabBar(this.tabBuilder(1, 'blue'))

        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#FFBF00')
        }.tabBar(this.tabBuilder(2, 'yellow'))

        TabContent() {
          Column().width('100%').height('100%').backgroundColor('#E67C92')
        }.tabBar(this.tabBuilder(3, 'pink'))
      }.onTabBarClick((index:number)=>{
        console.log('切换至',index)
      })
      .vertical(false)
      .barMode(BarMode.Fixed)
      .barWidth(360)
      .barHeight(56)
      .animationDuration(400)
      .onChange((index: number) => {
        this.currentIndex = index
      })
      .width(360)
      .height(296)
      .margin({ top: 52 })
      .backgroundColor('#F1F3F5')
    }.width('100%')
  }
}