Linq DistinctExtensions(linq根据条件去重)

public static class DistinctExtensions
    {
        public static IEnumerable<TSource> DistinctBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
        {
            HashSet<TKey> keys = new HashSet<TKey>();
            foreach (TSource element in source)
                if (keys.Add(keySelector(element)))
                    yield return element;
        }

    }

View Code