1 class Master
2 {
3 publicintId{ get;set;}
4 publicstringName{ get;set;}
5 publicintAge{ get;set;}
6 publicstringKongfu{ get;set;}
7 publicstringMenPai{ get;set;}
8 publicintLevel{ get;set;}
9 public overide string ToString()
10 {
11 return string.Fromat("Id:{0},Name:{1},Age:{2},Kongfu:{3},MenPai:{4},Level:{5}", Id, Name, Age, Kongfu, Menpai, Leve)
12 }
13 }
1 class KongFu
2 {
3 public int Id { get;set;}
4 public string Name { get;set;}
5 public int Power { get;set;}
6
7 public override string ToString()
8 {
9 return string.Format("Id:{0},Name:{1},Power:{2}", Id, Name, Power);
10 }
11 }
1 static void Main(String[] args)
2 {
3 var master =newList<Master>()
4 {
5 newMaster(){Id=1,Name="黃蓉",Age=18,Menpai="丐幫", Kongfu="打狗棒法",Level=9},
6 newMaster(){Id=2,Name="洪七公",Age=70,Menpai="丐幫", Kongfu="打狗棒法",Level=10},
7 newMaster(){Id=3,Name="郭靖",Age=22,Menpai="丐幫", Kongfu="降龍十八掌",Level=10},
8 newMaster(){Id=4,Name="任我行",Age=50,Menpai="明教", Kongfu="葵花寶典",Level=1},
9 newMaster(){Id=5,Name="東方不敗",Age=35,Menpai="明教", Kongfu="葵花寶典", Level=10},
10 newMaster(){Id=6,Name="林平之",Age=23,Menpai="華山", Kongfu="葵花寶典", Level=7},
11 newMaster(){Id=7,Name="岳不群", Age=50,Menpai="華山",Kongfu="葵花寶典",Level=8},
12 newMaster(){Id=8,Name="令狐沖",Age=23,Menpai="華山",Kongfu="獨孤九劍", Level=10},
13 newMaster(){Id=9,Name="梅超風",Age=23,Menpai="梅花島",Kongfu="九陰真經", Level=10},
14 newMaster(){Id=10,Name="黃藥師",Age=23,Menpai="梅花島",Kongfu="彈指神功",Level=10},
15 newMaster(){ Id = 11, Name = "風清揚", Age = 23, Menpai = "華山", Kongfu = "獨孤九劍", Level = 10 }
16 };
17 var kongfu =newList<KongFu>()
18 {
19 newKongFu(){Id=1,Name="打狗棒法", Power=95 },
20 newKongFu(){Id=2,Name="降龍十八掌",Power=100},
21 newKongFu(){Id=3,Name="葵花寶典", Power=100},
22 newKongFu(){Id=4,Name="獨孤九劍", Power=100},
23 newKongFu(){Id=5,Name="九陰真經", Power=100},
24 newKongFu(){Id=6,Name="彈指神功", Power=100},
25 };
26 }
【第一種】：找出Level大於8的列表來
var result = new List<Master>();
foreach (var item in master)
{
if (item.Level > 8)
{
result.Add(item);
}
}
foreach (var item in result)
{
Console.WriteLine(item.ToString());//ToString()不寫默認存在
}
Console.ReadKey();
//需要在 master類和KongFu中創建 ToString()方法，因為在查詢完以後進行遍歷（foreach）的時候h會出現以下錯誤
【第二種】：利用專業查詢語言查找並排序
//from：表示從哪個集合裡查找……where：查新條件……select：返回結果列表
var result2 = from m in master
where m.Level < 10//查詢條件
orderby m.Level//根據level進行升序排序
orderby m.Level descending//根據level進行降序排序
select m;
foreach (var item in result2)
{
Console.WriteLine(item);
}
Console.ReadKey();
【按條件查找並排序】
var ressult22 = from m in master.Where(m => m.Level < 10).OrderBy(m => m.Age)//OrderBy && OrderByDescending 升序和降序 排列
select m;
foreach (var item in ressult22)
{
Console.WriteLine(item);
}
Console.ReadKey();
【第三種】：調用函數的方法來實現查找功能
var result3 = master.Where(T1);
foreach (var item in result3)
{
Console.WriteLine(item);
}
Console.ReadKey();
//需要調用的類
static bool T1(Master m)
{
if (m.Level < 10)
{ return true; }
else
{ return false; }
}
【第四種】：利用lamada表達式查找
var result4 = master.Where(m => m.Level < 10);//lamada表達式 參數名=>表達式
foreach (var item in result4)
{
Console.WriteLine(item);
}
Console.ReadKey();
【第五種】：將兩個列表聯合起來，形成 Count(master) * Count(Kongfu) 的列表
var result5 = from m in master
from f in kongfu
select new { mm = m, ff = f };//
foreach (var item in result5)
{
Console.WriteLine(item);
}
Console.ReadKey()
【第六種】：查詢當 master.Level == Kongfu.Id，時兩個的信息
var result6 = from m in master
from f in kongfu
//where m.Level == f.Id
where m.Kongfu == f.Name && f.Power > 90
select new { mm = m, ff = f };
foreach (var item in result6)
{
Console.WriteLine(item);
}
Console.ReadKey();
【第七種】：實現master和Kongfu中屬性相等的信息輸出
var result7 = from m in master
//將kongfu列表中的信息放入k中，選出 m.Kongfu == k.Name的信息
join k in kongfu on m.Kongfu equals k.Name
select new { mm = m, kk = k };
foreach (var item in result7)
{
Console.WriteLine(item);
}
Console.ReadKey();
【第八種】：一人修煉一門功夫，一門功夫被多少人修煉
var result8 = from k in kongfu
join m in master on k.Name equals m.Kongfu
into groups//把武林高手分類，看看哪門功夫被人修煉的多
orderby groups.Count()//按照修煉人進行
select new { kongfu = k, count = groups.Count() };//groups.count：獲取到
foreach (var item in result8)
{
Console.WriteLine(item);
}
Console.ReadKey();
//將修煉功夫一樣的人放在一起並輸出master和kongfu的信息
var result = from k in kongfu
join m in master on k.Name equals m.Kongfu
select new { mm = m, kk = k };
foreach (var item in result)
{
Console.WriteLine(item);
}
Console.ReadKey();
【第九種】：按照自身幫派進行分組，
var result9 = from m in master
group m by m.Menpai//將門派分組，放到m中
into p//表示放到p中
select new { count = p.Count(), key = p.Key };//count = p.Count()表示這組有多少人
//key = p.Key表示這個是按照什麼分的，即關鍵字"Key"為Menpai
foreach (var item in result9)
{
Console.WriteLine(item);
}
Console.ReadKey();
【第十種】：確定序列中元素是否滿足條件
Any在內部循環遍歷每個元素
根據m=>m.Menpai判斷是否滿足條件
bool result10 = master.Any(m => m.Menpai == "丐幫");
Console.WriteLine(result10);
Console.ReadKey();
來自為知筆記(Wiz)
