Show/Hide Event

The show/hide event is triggered when a component is mounted or unmounted from the component tree. A component appears when mounted to the component tree and disappears when unmounted from the component tree.

NOTE

The APIs of this module are supported since API version 7. Updates will be marked with a superscript to indicate their earliest API version.

Events

Example

// xxx.ets
import prompt from '@ohos.prompt';

@Entry
@Component
struct AppearExample {
  @State isShow: boolean = true;
  @State changeAppear: string = 'Hide Text';
  private myText: string = 'Text for onAppear';

  build() {
    Column() {
      Button(this.changeAppear)
        .onClick(() => {
          this.isShow = !this.isShow;
        }).margin(15)
      if (this.isShow) {
        Text(this.myText).fontSize(26).fontWeight(FontWeight.Bold)
          .onAppear(() => {
            this.changeAppear = 'Hide Text';
            prompt.showToast({
              message: 'The text is shown',
              duration: 2000
            })
          })
          .onDisAppear(() => {
            this.changeAppear = 'Show Text';
            prompt.showToast({
              message: 'The text is hidden',
              duration: 2000
            })
          })
      }
    }.padding(30).width('100%')
  }
}