/// <summary> /// 使用 IList 的扩展方法 GroupBy 来获取来自哪些省份的数据 /// </summary> /// <param name="persons"></param> /// <returns></returns> public static List <string> GetProvincesGroupBy(Calculatedaverage persons) { var result = new List <string>(); foreach (var item in persons.GroupBy(x => x.Province)) { result.Add(item.Key); } return(result); }
/// <summary> /// 使用 IList 的扩展方法 GroupBy 每个省份有多少人 /// </summary> /// <param name="persons"></param> /// <returns></returns> public static List <PersonsInProvince> GetProvincesPersons(Calculatedaverage persons) { var result = new List <PersonsInProvince>(); foreach (var item in persons.GroupBy(x => x.Province)) { var data = new PersonsInProvince { ProvinceName = item.Key, Amount = item.Count() }; result.Add(data); } return(result); }