LINQ 学习笔记(04)

orderedby 用来对select的结果排序。

concat用来连接两个集合

 class CalendarEvent    {        public string Title { get; set; }        public DateTimeOffset StartTime { get; set; }        public TimeSpan Duration { get; set; }    }    class Program    {        static void Main(string[] args)        {            List<CalendarEvent> events = new List<CalendarEvent>            {                new CalendarEvent                {                    Title = "Swing Dancing at the South Bank",                    StartTime = new DateTimeOffset(2009,7,11,15,0,0, TimeSpan.Zero),                    Duration = TimeSpan.FromHours(4)                },                                new CalendarEvent                {                    Title = "Saturday Night Swing",                    StartTime = new DateTimeOffset(2009, 7, 11, 19, 30, 0, TimeSpan.Zero),                    Duration = TimeSpan.FromHours(6.5),                },                new CalendarEvent                {                    Title = "Formula 1 German Grand Prix",                    StartTime = new DateTimeOffset(2009,7,12,12,19,0, TimeSpan.Zero),                    Duration = TimeSpan.FromHours(3)                },                new CalendarEvent                {                    Title = "Swing Dance Picnic",                    StartTime = new DateTimeOffset(2009,7,12,15,0,0,TimeSpan.Zero),                    Duration = TimeSpan.FromHours(4)                },                new CalendarEvent                {                   Title = "Stompin' at the 100 Club",                   StartTime = new DateTimeOffset(2009,7,13,19,45,0,TimeSpan.Zero),                   Duration = TimeSpan.FromHours(5)                }            };            var eventsBystartTime = from ev in events                                    orderby ev.StartTime   // default ascending                                    select ev;            foreach (CalendarEvent ev in eventsBystartTime)            {                Console.WriteLine("-------------------------------");                Console.WriteLine(ev.Title);                Console.WriteLine(ev.StartTime);                Console.WriteLine(ev.Duration);            }            var eventsBystartTimeD = from ev in events                                    orderby ev.StartTime descending                                    select ev;            foreach (CalendarEvent ev in eventsBystartTimeD)            {                Console.WriteLine("-------------------------------");                Console.WriteLine(ev.Title);                Console.WriteLine(ev.StartTime);                Console.WriteLine(ev.Duration);            }            var eventsByStartTimeNoDate = from ev in events                                          orderby ev.StartTime.TimeOfDay                                          select ev;            foreach (CalendarEvent ev in eventsByStartTimeNoDate)            {                Console.WriteLine("-------------------------------");                Console.WriteLine(ev.Title);                Console.WriteLine(ev.StartTime);                Console.WriteLine(ev.Duration);            }            var eventsByTwoConditions = from ev in events                                        orderby ev.StartTime.Date, ev.Duration                                        select ev;            //var eventsByTwoConditions = events.OrderBy(ev => ev.StartTime).ThenBy(ev => ev.Duration);            foreach (CalendarEvent ev in eventsByTwoConditions)            {                Console.WriteLine("-------------------------------");                Console.WriteLine(ev.Title);                Console.WriteLine(ev.StartTime);                Console.WriteLine(ev.Duration);            }            var allEvents = eventsBystartTime.Concat(eventsBystartTimeD);            foreach (CalendarEvent ev in allEvents)            {                Console.WriteLine("-------------------------------");                Console.WriteLine(ev.Title);                Console.WriteLine(ev.StartTime);                Console.WriteLine(ev.Duration);            }        }    }