LINQ简单案例

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace linQ
 8 {
 9     class Kongfu
10     {
11         public int id;//武学ID
12         public string name;//武学名称
13         public int power;//伤害
14 
15         public override string ToString()
16         {
17             return "ID为" + id + "名字" + name + "伤害" + power;
18         }
19     }
20 }

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel.Design;
 4 using System.Linq;
 5 using System.Text;
 6 using System.Threading.Tasks;
 7 
 8 namespace linQ
 9 {
10     class Program
11     {
12         static void Main(string[] args)
13         {
14             //创建一个LIST列表，并插入数据
15             List<Master> master=new List<Master>()
16             {
17                 new Master(){id=1,kongfu="葵花宝典",level =10,name = "东方不败"},
18                 new Master(){id=2,kongfu="独孤九剑",level = 4,name ="令狐冲"},
19                 new Master(){id=3,kongfu ="辟邪剑谱",level = 2,name="林平之"},
20                 new Master(){id=4,kongfu="葵花宝典",level =8,name="岳不群"}
21 
22                };
23             List<Kongfu> kongfu=new List<Kongfu>()
24             {
25                 new Kongfu(){id=1,name ="葵花宝典",power =300},
26                 new Kongfu(){id=2,name = "独孤九剑",power = 200},
27                 new Kongfu(){id=3,name = "辟邪剑谱",power = 150}
28 
29             };
30             //LINQ方法查询数据 
31             /*var res = from m in master
32                 where m.level > 8//查询武学等级大于8的人的相关数据
33                 select m;*/
34             //如果查询两个表相关的数据
35           //  var res = from master1 in master
36              //   from kongfu1 in kongfu
37                 //查询等级大于4并且上大于武学伤害大于200的相关数据
38                // where master1.level > 4 && kongfu1.power > 200
39                 //select new {a=master1,b=kongfu1};
40                 //select master1.name;//只输出修炼人的名称
41 
42             //如果要对结果根据等级进行排序,查询修炼葵花宝典的人，并进行等级排序
43             /*var res1 = from m in master
44                 from n in kongfu
45                 where m.kongfu == "葵花宝典"
46                 orderby m.level 
47                 select m;*/
48             //如果用Join on方法进行连接,根据两个类中的武学进行连接
49             var res2 = from m in master
50                 join n in kongfu on m.kongfu equals n.name
51                 where m.level > 8
52                 select m.name;
53             
54             
55                        
56             //用循环遍历输出显示想要查询的结果
57             foreach (var a in res2)
58             {
59                 Console.WriteLine(a);
60             }
61             Console.ReadKey();
62         }
63     }
64 }