int[] str = { , , , , , , , , , , , ,  };

            var elist = from s in str

                        where s %  ==

                        select s;

            foreach (int i in elist)

            {

                Console.WriteLine("偶数有:{0}", i);

            }

            Console.ReadKey();

            int[] str = { , , , , , , , , , , , ,  };

            var elist = from s in str

                        where s %  ==

                        orderby s descending ////查询所有偶数并倒序排序，就是从大到小排序。

                        select s;

            foreach (int i in elist)

            {

                Console.WriteLine("偶数有:{0}", i);

            }

    class Student

    {

        public string name { get; set; }

        public string sex { get; set; }

        public int age { get; set; }

    }

            List<Student> list = new List<Student>()

            {

                new Student(){name=@"haha",sex="女",age=},

                new Student(){name=@"hehe",sex="女",age=},

                new Student(){name=@"heihei",sex="男",age=}

            };

            //var stu = from s in list

            //          where s.age > 10

            //          select s;

            //foreach (var bb in stu)

            //{

            //    Console.WriteLine("{0},{1},{2}", bb.name, bb.age, bb.sex);

            //}

            //将查询结果直接放入一个新的对象

            var stu = from s in list

                      where s.age >

                      select new { Newname = s.name, Newsex = s.sex, Newage = s.age };

            foreach (var bb in stu)

            {

                Console.WriteLine("{0},{1},{2}", bb.Newname, bb.Newage, bb.Newsex);

            }

            string[] arr = { "qwewrtyywe", "asdfghkl", "zxcvbnm", "abcqqqqqq" };

            IEnumerable<string> str = from s in arr

                                      where s.Length >

                                      select s;

            foreach (var ab in str)

            {

                Console.WriteLine(ab);

            }