using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LINQ_into
{
/// <summary>
/// LINQ group
/// </summary>
class Program
{
static void Main(string[] args)
{
List<GustInfo> gList = new List<GustInfo>()
{
new GustInfo(){ Name="DebugLZQ",Age=26,Tel="187********"},
new GustInfo(){ Name="Sarah",Age=25,Tel="159********"},
new GustInfo(){ Name="Jerry",Age=35,Tel="135********"},
new GustInfo(){ Name="M&M",Age=16,Tel="136********"},
new GustInfo(){ Name="DebugMan",Age=26,Tel="136********"},
new GustInfo(){ Name="Jerry&Tom",Age=19,Tel="136********"},
};
//1.into用于group子句
var query = from guest in gList
group guest by guest.Name.Substring(0, 1) into grguest
orderby grguest.Key descending
select grguest;
var query2 = from guest in gList
group guest by guest.Name.Substring(0, 1) into grguest
orderby grguest.Key ascending
select grguest;
//2.select 子句中的into子句
var query3 = from guest in gList
select new { NewName = guest.Name, NewAge = guest.Age } into newguest
orderby newguest.NewAge
select newguest;
foreach (var guestGroup in query)
{
Console.WriteLine("分组键：{0}",guestGroup.Key );
foreach (var g in guestGroup)
{
Console.WriteLine("{0} 电话:{1}",g.Name,g.Tel );
}
}
Console.ReadKey(false);
foreach (var newg in query3)
{
Console.WriteLine("{0} 年龄：{1}",newg.NewName,newg.NewAge );
}
Console.ReadKey(false);
}
}
}
程序运行结果如下：
6.orderby子句、thenby子句
LINQ可以按照元素的一个或多个属性对元素进行排序。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LINQ_orderby
{
class Program
{
/// <summary>
/// LINQ orderby (ascending descending)
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
List<GustInfo> gList = new List<GustInfo>()
{
new GustInfo(){ Name="DebugLZQ",Age=26,Tel="187********"},
new GustInfo(){ Name="Sarah",Age=25,Tel="159********"},
new GustInfo(){ Name="Jerry",Age=35,Tel="135********"},
new GustInfo(){ Name="M&M",Age=16,Tel="136********"},
new GustInfo(){ Name="DebugMan",Age=26,Tel="136********"},
new GustInfo(){ Name="Jerry&Tom",Age=19,Tel="136********"},
};
//按照年龄排序
var query = from guest in gList
orderby guest.Age
select guest;
var query1 = from guest in gList
orderby guest.Age ascending
select guest;
var query2 = from guest in gList
orderby guest.Age descending
select guest;
//按照年龄进行排序，按照名字字数进行次要排序
var query3 = from guest in gList
orderby guest.Age, guest.Name.Length
select guest;
var query4 = from guest in gList
orderby guest.Age descending , guest.Name.Length ascending
select guest;
var query5 = from guest in gList
orderby guest.Age, guest.Name.Length,guest.Tel
select guest;
foreach (var guest in query2)
{
Console.WriteLine("{0} 年龄：{1} 电话：{2}",guest.Name,guest.Age,guest.Tel );
}
Console.ReadKey(false);
foreach (var guest in query4)
{
Console.WriteLine("{0} 年龄：{1} 电话：{2}", guest.Name, guest.Age, guest.Tel);
}
Console.ReadKey(false);
}
}
}
