Linq简单的查询,扩展方法-创新互联
----------------------------------------------------Racer.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;
namespace ConsoleApplication1
{
[Serializable]
public class Racer:IComparable,IFormattable
{
public string FirstName { get; private set; }//第一个武将
public string LastName { get; private set; }//第二个武将
public int Wins { get; private set; }//赢得次数
public string Country { get; private set; }//国家
public int Starts { get; private set; }//开始
public string[] Arms { get; private set; }//武器
public int[] Years { get; private set; }//年份
public Racer(string firstname = "", string lasename = "", int wins = 0, string country = "", int starts = 0, IEnumerable Arms = null, IEnumerable years = null)
{
this.FirstName = firstname;
this.LastName = lasename;
this.Wins = wins;
this.Country = country;
this.Starts = starts;
List LArms = new List();
foreach (var item in Arms)
{
LArms.Add(item);
}
this.Arms = LArms.ToArray();
List Lyears = new List();
foreach (var item in years)
{
Lyears.Add(item);
}
this.Years = Lyears.ToArray();
}
public int CompareTo(Racer other)
{
if (other == null) throw new ArgumentNullException("对象不能为空");
return this.Wins.CompareTo(other.Wins);
}
public string ToString(string format, IFormatProvider formatProvider)
{
switch (format)
{
case "":
return ToString();
case "C":
StringBuilder sb = new StringBuilder();
foreach (var item in Arms)
{
sb.Append(item + ",");
}
return sb.ToString().TrimEnd(',');
case "Y":
StringBuilder sb2 = new StringBuilder();
foreach (var item in Years)
{
sb2.Append(item + ",");
}
return sb2.ToString().TrimEnd(',');
default:
return ToString();
}
}
public override string ToString()
{
return string.Format("第一个赛手：{0},最后一个赛手：{1},赢的次数：{2},国家：{3},开始：{4}",this.FirstName,this.LastName,this.Wins.ToString(),this.Country,this.Starts.ToString());
}
}
} ----------------------------------------------------Team.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication1
{
public class Team
{
public string Name { get; private set; }//团队名称
public int[] Years { get; private set; }
public Team(string name,params int[] years)
{
this.Name = name;
this.Years = years;
}
}
}----------------------------------------------------Formula.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication1
{
public static class Formula
{
private static List racers;
private static List team;
public static IList GetChampions()
{
if (racers == null)
{
racers = new List();
racers.Add(new Racer("张飞", "关羽", 100, "蜀国", 10, new string[] { "丈八蛇矛", "青龙偃月刀" }, new int[] { 200, 201, 202 }));
racers.Add(new Racer("黄忠", "魏延", 80, "蜀国", 10, new string[] { "穿杨弓", "大***" }, new int[] {203}));
racers.Add(new Racer("许褚", "典韦", 95, "魏国", 10, new string[] { "大铁锤", "双戟" }, new int[] { 195, 212 }));
racers.Add(new Racer("张辽", "徐晃", 90, "魏国", 10, new string[] { "长把子刀", "长把子斧" }, new int[] { 205, 106, 215 }));
racers.Add(new Racer("程普", "黄盖", 96, "吴国", 10, new string[] { "龙虎鞭", "大刀" }, new int[] { 190, 191, 202,207 }));
racers.Add(new Racer("周泰", "太史慈", 88, "吴国", 10, new string[] { "无敌身躯", "火箭枪" }, new int[] { 195, 196, 197 }));
}
return racers;
}
public static IList GetConstructorChampions()
{
if (team == null)
{
team = new List();
team.Add(new Team("兄弟队", new int[] { 200, 201, 202 }));
team.Add(new Team("死党队", new int[] { 203 }));
team.Add(new Team("虎营队", new int[] { 195, 212 }));
team.Add(new Team("良将队", new int[] { 205, 106, 215 }));
team.Add(new Team("老将队", new int[] { 190, 191, 202, 207 }));
team.Add(new Team("不死队", new int[] { 195, 196, 197 }));
}
return team;
}
}
} ----------------------------------------------------主程序
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
var query = from r in Formula.GetChampions()
where r.Country == "蜀国"
orderby r.Wins descending
select r;
foreach (var item in query)
{
Console.WriteLine("{0}",item);
}
Console.ReadKey();
//===============================================扩展方法
List RacersCondition = new List(Formula.GetChampions());
//Where:扩展方法，用于筛选
//OrderBy:扩展方法，用于排序
//Select：扩展方法,将值投放到新表中
IEnumerable RacersResult = RacersCondition.Where(r => r.Country == "吴国").OrderBy(r => r.Wins).Select(r => r);
foreach (var item in RacersResult)
{
Console.WriteLine(item);
}
Console.ReadKey();
}
}
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