HarmonyOS ArkTS语法适配报错

firstRequestParams?: Record<string, string>

aboutToAppear(): void {
  let params: Record<string, string> = {}
if (this.firstRequestParams) {
  Object.keys(this.firstRequestParams).forEach(key => {
    params[key] = this.firstRequestParams[key];
  })
}
}

上面的代码会报错：Object is possibly ‘undefined’，但是明明代码在外层已经判断了不为空，这时候还需要在里面再次判断不为空或者强制使用！才不报错

ERROR: ArkTS:ERROR File: /Users/xxx/Documents/Work/module/module_group/src/main/ets/viewmodel/GroupTabFeedListViewModel.ets:24:25Object is possibly ‘undefined’.