HarmonyOS TextInput如何主动弹出键盘？

@Entry  
@Component  
struct SearchPage {  
  aboutToAppear(): void {  
    setTimeout(() => {  
      focusControl.requestFocus('AAA')  
    },1000)  
  }  
  
  build() {  
    Row() {  
      Column() {  
        TextInput().enableKeyboardOnFocus(true).key('AAA')  
  
      }  
      .width('100%')  
    }  
    .height('100%')  
  }  
}