查找List中的某个值，可以使用循环遍历对比，查找出结果。C#中提供了Find方法，可以直接使用，只要查找条件传入就可。如下：

    class Program
    {
        public static void Main(string[] args)
        {
            List<User> userCollection = new List<User>();

            userCollection.Add(new User(1, "testOne"));

            userCollection.Add(new User(2, "testTwo"));

            userCollection.Add(new User(3, "testThree"));

            User resultUser = userCollection.Find(

                delegate(User user)
                {
                    //return user.UserID == 0;

                    return user.UserID == 1 && user.UserName.Equals("testOne");
                });

            Console.WriteLine(resultUser != null ? 
                
                resultUser.UserID + System.Environment.NewLine + resultUser.UserName : "没有查找到");

            Console.ReadLine();
        }
    }

    public class User
    {
        private int userID = 0;

        private string userName = string.Empty;

        public int UserID
        {
            get
            {
                return this.userID;
            }
        }

        public string UserName
        {
            get
            {
                return this.userName;
            }
        }

        public User(int userID, string userName)
        {
            this.userID = userID;

            this.userName = userName;
        }
    }

结果：