list集合的去重操作
代码 class ListDistinctDemo { static void Main(string[] args) { List<Person> personList = new List<Person>(){ new Person(3),//重复数据 new Person(3), new Person(2), new Person(1) }; //使用匿名方法 List<Person> delegateList = personList.Distinct(new Compare<Person>( delegate(Person x, Person y) { if (null == x || null == y) return false; return x.ID == y.ID; })).ToList(); delegateList.ForEach(s => Console.WriteLine(s.ID)); //使用 Lambda 表达式 List<Person> lambdaList = personList.Distinct(new Compare<Person>( (x, y) => (null != x && null != y) && (x.ID == y.ID))).ToList(); lambdaList.ForEach(s => Console.WriteLine(s.ID)); //排序 personList.Sort((x, y) => x.ID.CompareTo(y.ID)); personList.ForEach(s => Console.WriteLine(s.ID)); } } public class Person { public int ID { get; set; } public string Name { get; set; } public Person(int id) { this.ID = id; } } public delegate bool EqualsComparer<T>(T x, T y); public class Compare<T> : IEqualityComparer<T> { private EqualsComparer<T> _equalsComparer; public Compare(EqualsComparer<T> equalsComparer) { this._equalsComparer = equalsComparer; } public bool Equals(T x, T y) { if (null != this._equalsComparer) return this._equalsComparer(x, y); else return false; } public int GetHashCode(T obj) { return obj.ToString().GetHashCode(); } }
时间: 2024-10-29 19:09:37