HarmonyOS LazyForEach

@State @Watch('onDataChange') dataSource: WaterFlowDataSource = new WaterFlowDataSource() 
@State totalCount: number = this.dataSource.totalCount() 
onDataChange(){ 
  this.totalCount = this.dataSource.totalCount() 
} 
 
build() { 
  if(this.totalCount > 0){ 
    Text(`${this.totalCount}`) 
  } 
}