var expectedList = list1.Except(list2);

r.AddRange(i);

r.AddRange(j);

                                List<string> listold = itemtocheck.AuidtSearchWord.Split(',').ToList(); //旧的搜索词List<string> listnew = NewsearchWords.Split(',').ToList(); //新的搜索词listold.RemoveAll(c => listnew.Contains(c));tempmixwords = string.Join(",", listold.Distinct());

private static IEnumerable<TSource> ExceptIterator<TSource>(IEnumerable<TSource> first, IEnumerable<TSource> second, IEqualityComparer<TSource> comparer)
{Set<TSource> set = new Set<TSource>(comparer);foreach (TSource source in second)set.Add(source);foreach (TSource source in first){if (set.Add(source))yield return source;}
}public interface IEqualityComparer<in T>
{/// <summary>确定指定的对象是否相等。</summary>/// <returns>如果指定的对象相等，则为 true；否则为 false。</returns>/// <param name="x">要比较的第一个类型为 <paramref name="T" /> 的对象。</param>/// <param name="y">要比较的第二个类型为 <paramref name="T" /> 的对象。</param>
  [__DynamicallyInvokable]bool Equals(T x, T y);/// <summary>返回指定对象的哈希代码。</summary>/// <returns>指定对象的哈希代码。</returns>/// <param name="obj">/// <see cref="T:System.Object" />，将为其返回哈希代码。</param>/// <exception cref="T:System.ArgumentNullException">/// <paramref name="obj" /> 的类型为引用类型，<paramref name="obj" /> 为 null。</exception>
  [__DynamicallyInvokable]int GetHashCode(T obj);
}

public class DeliverySchedulerComparer : IEqualityComparer<DeliverySchedulerDO>
{private static readonly DeliverySchedulerComparer _comparer = new DeliverySchedulerComparer();public static DeliverySchedulerComparer Instance(){return _comparer;}public bool Equals(DeliverySchedulerDO x, DeliverySchedulerDO y){return x.DeliveryLineId == y.DeliveryLineId &&x.DeliveryManId == y.DeliveryManId;}public int GetHashCode(DeliverySchedulerDO obj){string code = obj.DeliveryLineId.ToString() + obj.DeliveryManId.ToString();return code.GetHashCode();}//var invalidSchedulers = existsSchedulers.Except(dmsSchedulers, DeliverySchedulerComparer.Instance()).ToList();

int[] numbers = { 3, 5, 7 };
string[] words = { "three", "five", "seven", "ignored" };
IEnumerable<string> zip = numbers.Zip (words, (n, w) => n + "=" + w);// 产生的sequence包含如下元素
// 3=three
// 5=five
// 7=seven