C#List根据时间排序并且去除重复值

public class DateDto
{public int Id { get; set; }public string BId { get; set; }public string Name { get; set; }public DateTime CreateTime { get; set; }
}

对这个类中的Cretetime进行排序，并且保留最新添加进来的值，首先要写一个自定义的类，排序类

public class PeopleAgeComparer : IComparer<DateDto>
{public int Compare(DateDto dto,DateDto dto1){TimeSpan sp = dto.CreateTime - dto1.CreateTime;if (sp.Days > 0){return -1;} else if (sp.Days < 0){return 1;}else{return 0;}}
}

去重类

 public class Compare<T, C> : IEqualityComparer<T>{private Func<T, C> _getField;public Compare(Func<T, C> getfield){this._getField = getfield;}public bool Equals(T x, T y){return EqualityComparer<C>.Default.Equals(_getField(x), _getField(y));}public int GetHashCode(T obj){return EqualityComparer<C>.Default.GetHashCode(this._getField(obj));}}public static class CommonHelper{/// <summary>/// 自定义Distinct扩展方法/// </summary>/// <typeparam name="T">要去重的对象类</typeparam>/// <typeparam name="C">自定义去重的字段类型</typeparam>/// <param name="source">要去重的对象</param>/// <param name="getfield">获取自定义去重字段的委托</param>/// <returns></returns>public static IEnumerable<T> MyDistinct<T, C>(this IEnumerable<T> source, Func<T, C> getfield){return source.Distinct(new Compare<T, C>(getfield));}}

操作

class Program{//第一步按照时间顺序排序 //第二步 去除重复得保留最新时间static void Main(string[] args){List<DateDto> dateDtos = new List<DateDto>();DateDto dateDto1 = new DateDto(){Id = 1,BId = "0001",Name = "设备1",CreateTime = DateTime.Parse("2020-9-27")};DateDto dateDto2 = new DateDto(){Id = 1,BId = "0001",Name = "设备1",CreateTime = DateTime.Parse("2020-9-28")};dateDtos.Add(dateDto1);dateDtos.Add(dateDto2);//foreach (var item in dateDtos)//{//    Console.WriteLine(item.CreateTime);//}//      List<People> peoples = new List<People>()//      {//           new People() {age = 11, name="alun", sex = "男"},//           new People() {age=25, name = "陈敬桃", sex = "男"},//           new People() {age=9, name = "惠安", sex = "男"},//            new People() {age = 45, name = "小票", sex = "女"},//      new People() {age=3, name = "晓鸥", sex = "女"},//  new People() {age=70, name = "望谟", sex = "男"}//};dateDtos.Sort(new PeopleAgeComparer());dateDtos = dateDtos.MyDistinct(c => c.Id).ToList();foreach (var item in dateDtos){Console.WriteLine(item.CreateTime);}Console.ReadKey();}}