Ling && Lambda

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test_Lambda_Linq
{
    class Program
    {
        static List<Person> PersonList = new List<Person>()
            {
                new Person(){ Id=1, Age=10, Name="James", Gender="Male"},
                new Person(){ Id=2, Age=20, Name="Harden", Gender="Male" },
                new Person(){ Id=3, Age=30, Name="George", Gender="Female"},
                new Person(){ Id=4, Age=40, Name="Ball", Gender="Female"},
                new Person(){ Id=5, Age=50, Name="Kobe", Gender="Male"},
                new Person(){ Id=6, Age=60, Name="Fames", Gender="Male"},
                new Person(){ Id=7, Age=70, Name="Garden", Gender="Male" },
                new Person(){ Id=8, Age=80, Name="Deorge", Gender="Female"},
                new Person(){ Id=9, Age=90, Name="Hall", Gender="Female"},
                new Person(){ Id=10, Age=100, Name="Dobe", Gender="Male"},
                new Person(){ Id=11, Age=110, Name="Lames", Gender="Male"},
                new Person(){ Id=12, Age=120, Name="Parden", Gender="Male" },
                new Person(){ Id=13, Age=130, Name="Keorge", Gender="Female"},
                new Person(){ Id=14, Age=140, Name="Yall", Gender="Female"},
                new Person(){ Id=15, Age=150, Name="Robe", Gender="Male"}
            };
        static List<Children> ChildList = new List<Children>()
        {
            new Children(){ Id=1, Name="Tomas", Age=5, Class=2, Gender="Female"},
            new Children(){ Id=2, Name="James", Age=10, Class=1, Gender="Male"},
            new Children(){ Id=3, Name="Jungle", Age=12, Class=3, Gender="Male"}
        };
        static void Main(string[] args)
        {
            //PersonList.Reverse();//全盘逆序
            //PersonList.Reverse(0,4);//指定范围逆序
            #region Lambda
            #region Sort排序
            //ServiceInvoke.Invoke(() =>
            //{
            //    foreach (var p in PersonList)
            //    {
            //        Console.WriteLine(p.Name);
            //    }
            //});

            //PersonList.Sort((p1, p2) => { return p1.Age - p2.Age; });
            //PersonList.Sort((p1, p2) =>  p1.Age - p2.Age );//排序

            //ServiceInvoke.Invoke(() =>
            //{
            //    foreach (var p in PersonList)
            //    {
            //        Console.WriteLine(p.Name);
            //    }
            //});
            #endregion

            #region Where筛选高手
            //ServiceInvoke.Invoke(() =>
            //{
            //    List<Person> pTemp = PersonList.Where(p => p.Age > 20 && p.Gender == "Male").ToList();
            //    foreach (var p in pTemp)
            //    {
            //        Console.WriteLine(p.Name + " is " + p.Age + " years old ");
            //    };
            //    PersonList.ForEach(p => Console.WriteLine(p.Name));
            //});
            #endregion

            #region Select投影大牛---查询投影
            //ServiceInvoke.Invoke(() => 
            //{
            //    List<Person> pTemp = PersonList.Where(p => p.Gender == "Male").Select(p => (Person)new LitePerson() { Name = p.Name , Age=p.Age}).ToList();
            //    foreach (var p in pTemp)
            //    {
            //        Console.WriteLine(p.Name + " is " + p.Age + " years old ");
            //    };
            //    PersonList.ForEach(p => Console.WriteLine(p.Name));
            //});
            #endregion

            #region OrderBy排序 第二次用ThenBy排序
            //ServiceInvoke.Invoke(() =>
            //{
            //    Console.WriteLine("Initial Order:"); PersonList.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old "));//原来
            //    List<Person> pTempDefault = PersonList.OrderBy(p => p.Age).ToList(); Console.WriteLine("Default Order:");//默认由小到大---升序
            //    pTempDefault.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old "));//排序后

            //    //单条件降序
            //    List<Person> pTempDescending = PersonList.OrderByDescending(p => p.Age).ToList(); Console.WriteLine("Descending Order:");//降序
            //    pTempDescending.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old "));

            //    //多条件综合排序
            //    List<Person> pTempOrderBy_ThenByDescending = PersonList.OrderBy(p => p.Age).ThenByDescending(p => p.Id).ToList(); Console.WriteLine("OrderBy_ThenByDescending Order:");
            //    pTempOrderBy_ThenByDescending.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
            //});
            #endregion

            #region Join 多个数据集(>=2)   
            //ServiceInvoke.Invoke(() =>
            //{
            //    var joinedList = PersonList.Join(ChildList, p => p.Id, c => c.Id, (p, c) =>
            //    new { //匿名对象
            //        ParentID = p.Id,
            //        ChildID = c.Id,
            //        ParentName = p.Name,
            //        ChildName = c.Name
            //    }).ToList();
            //    joinedList.ForEach(j => Console.WriteLine(" ParentID: " + j.ParentID + " ChildID: " + j.ChildID + " ParentName: " + j.ParentName + " ChildName: " + j.ChildName));
            //});
            #endregion

            #region GroupBy
            //ServiceInvoke.Invoke(() =>
            //{
            //    IEnumerable<IGrouping<string, Person>> groups = PersonList.GroupBy(p => p.Gender);
            //    IList<IGrouping<string, Person>> groupList = groups.ToList();
            //    foreach (var g in groupList)
            //    {
            //        //Key是分组依据的类型---Gender
            //        Console.WriteLine("Group:{0}", g.Key=="Male" ? "Male" : "Female");
            //        foreach (Person p in g)
            //        {
            //            Console.WriteLine(p.Name + " is " + p.Gender);
            //        }
            //    }
            //});
            #endregion

            #region Skip与Take
            //实现分页
            //ServiceInvoke.Invoke(()=> 
            //{
            //    Console.WriteLine("First Page:");
            //    var firstPageData = GetPagedListByIndex(1,5);
            //    firstPageData.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
            //    Console.WriteLine("Second Page:");
            //    var secondPageData = GetPagedListByIndex(2, 5);
            //    secondPageData.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
            //    Console.WriteLine("Third Page:");
            //    var thirdPageData = GetPagedListByIndex(1, 5);
            //    thirdPageData.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
            //});
            #endregion
            #endregion

            #region Linq

            #region 基本查询
            //ServiceInvoke.Invoke(()=> 
            //{
            //    var maleList = from p in PersonList
            //                   where p.Gender == "Male"
            //                   select p;
            //    maleList.ToList().ForEach(p => Console.WriteLine(p.Name + " is " + p.Gender));
            //});
            #endregion

            #region 排序条件查询
            //ServiceInvoke.Invoke(() =>
            //{
            //    var orderList = from p in PersonList
            //                   orderby p.Age descending//先按年龄排序
            //                   orderby p.Name ascending//在上面的基础上按姓名排序
            //                   select p;
            //    orderList.ToList().ForEach(p => Console.WriteLine(p.Name + " is " + p.Age));
            //});
            #endregion

            #region 连接查询
            //ServiceInvoke.Invoke(() =>
            //{
            //    var joinedList = from p in PersonList
            //                     join c in ChildList
            //                     on p.Id equals c.Id
            //                     select new
            //                     {
            //                         Person = p,
            //                         Child = c
            //                     };
            //    joinedList.ToList().ForEach(p => Console.WriteLine(" Person.Name is " + p.Person.Name + " Child.Name is " + p.Child.Name + " And Id is: "+ p.Child.Id));
            //});
            #endregion

            #region 分组查询
            ServiceInvoke.Invoke(() =>
            {
                var groupList = from p in PersonList
                                 group p by p.Gender;
                foreach (var g in groupList)
                {
                    Console.WriteLine($"Group:{g.Key}");
                    foreach (var item in g)
                    {
                        Console.WriteLine(item.Name + " is "+ item.Gender);
                    }
                }
            });
            #endregion

            #endregion
        }

        static List<Person> GetPagedListByIndex(int pageIndex, int pageSize)
        {
            List<Person> dataList = PersonList;
            return dataList.Skip((pageIndex - 1) * pageSize).Take(pageSize).ToList();
        }
    }
}