public class CommonEqualityComparer<T, V> : IEqualityComparer<T>{private Func<T, V> keySelector;
public CommonEqualityComparer(Func<T, V> keySelector){this.keySelector = keySelector;}
public bool Equals(T x, T y){return EqualityComparer<V>.Default.Equals(keySelector(x), keySelector(y));}
public int GetHashCode(T obj){return EqualityComparer<V>.Default.GetHashCode(keySelector(obj));}}/// <summary>/// List去重复/// </summary>public static class DistinctExtensions{public static IEnumerable<T> Distinct<T, V>(this IEnumerable<T> source, Func<T, V> keySelector){return source.Distinct(new CommonEqualityComparer<T, V>(keySelector));}}
调用示例：
result = result.Distinct(p => p.groupid).OrderByDescending(m=>m.addtime).ToList();
