List<User> list = new List<User>() { new User{id=1 }, new User{id=2 }, new User{id=3 }, }; list.ForEach(p => Console.WriteLine(p.id));//等同于forearth //里面写判断 list.ForEach(p => { if (p.id==2) { Console.WriteLine(p.id.ToString()); } } );
public class User { public int id { get; set; } public string name { get; set; } public int parentId { get; set; } }