List实体去重分组：

实体去重分组：

//实体类
public class Province
    {
        public string id { get; set; }
        public string name { get; set; }
    }
//过滤
List<Province> newprovinceSelect = provinceSelect.GroupBy(p => p.id).Select(p => new Province { id = p.Key, name = p.FirstOrDefault().name }).ToList();