HarmonyOS viewModal demo问题

@Entry 
@Component 
struct Index { 
  @State viewModel: IndexModel = new IndexModel(); 
  build() { 
    Column() { 
      Text(this.viewModel.text1Value).backgroundColor("#faf").fontSize(25).onClick(() => { 
        this.viewModel.updateText1("Text1已更新") 
      }).onAreaChange((event) => { 
        console.log('text1 onAreaChange') 
      }) 
      Text(this.viewModel.text2Value).backgroundColor("#afa").fontSize(25).onClick(() => { 
        this.viewModel.updateText2("Text2已更新") 
      }).onAreaChange((event) => { 
        console.log('text2 onAreaChange') 
      }) 
    } 
    .alignItems(HorizontalAlign.Start) 
  } 
}