HarmonyOS-鸿蒙app开发—ArkTs基础挂载卸载事件

HarmonyOS-鸿蒙app开发—ArkTs基础挂载卸载事件

onAppear(event: () => void)  组件挂载显示时触发此回调。

onDisappear(event: () => void)  组件卸载消失时触发此回调。

index.ets

import prompt from '@ohos.prompt';
@Entry
@Component
struct Index {
  @State message: string = '炫码科技'
  @State changeAppear: string = 'Hide Text';
  build() {
    Row()
    {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .onAppear(() => {  //挂载事件
            this.changeAppear = 'Hide Text';
            prompt.showToast({
              message: 'The text is shown',
              duration: 2000
            })
          })
          .onDisAppear(() => { //卸载事件
            this.changeAppear = 'Show Text';
            prompt.showToast({
              message: 'The text is hidden',
              duration: 2000
            })
          })
        Button("点我")  
          .margin(20)
          .backgroundColor('red')
          .onClick(()=>  //按钮点击事件
          {
            prompt.showToast({
              message: '鸿蒙app开发',
              duration: 5000
            })
          })
      }
      .width('100%')
    }
    .height('100%')
    .backgroundColor('green')
  }
}