1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using System.Threading.Tasks;
6
7 namespace Test_Lambda_Linq
8 {
9 class Program
10 {
11 static List<Person> PersonList = new List<Person>()
12 {
13 new Person(){ Id=1, Age=10, Name="James", Gender="Male"},
14 new Person(){ Id=2, Age=20, Name="Harden", Gender="Male" },
15 new Person(){ Id=3, Age=30, Name="George", Gender="Female"},
16 new Person(){ Id=4, Age=40, Name="Ball", Gender="Female"},
17 new Person(){ Id=5, Age=50, Name="Kobe", Gender="Male"},
18 new Person(){ Id=6, Age=60, Name="Fames", Gender="Male"},
19 new Person(){ Id=7, Age=70, Name="Garden", Gender="Male" },
20 new Person(){ Id=8, Age=80, Name="Deorge", Gender="Female"},
21 new Person(){ Id=9, Age=90, Name="Hall", Gender="Female"},
22 new Person(){ Id=10, Age=100, Name="Dobe", Gender="Male"},
23 new Person(){ Id=11, Age=110, Name="Lames", Gender="Male"},
24 new Person(){ Id=12, Age=120, Name="Parden", Gender="Male" },
25 new Person(){ Id=13, Age=130, Name="Keorge", Gender="Female"},
26 new Person(){ Id=14, Age=140, Name="Yall", Gender="Female"},
27 new Person(){ Id=15, Age=150, Name="Robe", Gender="Male"}
28 };
29 static List<Children> ChildList = new List<Children>()
30 {
31 new Children(){ Id=1, Name="Tomas", Age=5, Class=2, Gender="Female"},
32 new Children(){ Id=2, Name="James", Age=10, Class=1, Gender="Male"},
33 new Children(){ Id=3, Name="Jungle", Age=12, Class=3, Gender="Male"}
34 };
35 static void Main(string[] args)
36 {
37 //PersonList.Reverse();//全盘逆序
38 //PersonList.Reverse(0,4);//指定范围逆序
39 #region Lambda
40 #region Sort排序
41 //ServiceInvoke.Invoke(() =>
42 //{
43 // foreach (var p in PersonList)
44 // {
45 // Console.WriteLine(p.Name);
46 // }
47 //});
48
49 //PersonList.Sort((p1, p2) => { return p1.Age - p2.Age; });
50 //PersonList.Sort((p1, p2) => p1.Age - p2.Age );//排序
51
52 //ServiceInvoke.Invoke(() =>
53 //{
54 // foreach (var p in PersonList)
55 // {
56 // Console.WriteLine(p.Name);
57 // }
58 //});
59 #endregion
60
61 #region Where筛选高手
62 //ServiceInvoke.Invoke(() =>
63 //{
64 // List<Person> pTemp = PersonList.Where(p => p.Age > 20 && p.Gender == "Male").ToList();
65 // foreach (var p in pTemp)
66 // {
67 // Console.WriteLine(p.Name + " is " + p.Age + " years old ");
68 // };
69 // PersonList.ForEach(p => Console.WriteLine(p.Name));
70 //});
71 #endregion
72
73 #region Select投影大牛---查询投影
74 //ServiceInvoke.Invoke(() =>
75 //{
76 // List<Person> pTemp = PersonList.Where(p => p.Gender == "Male").Select(p => (Person)new LitePerson() { Name = p.Name , Age=p.Age}).ToList();
77 // foreach (var p in pTemp)
78 // {
79 // Console.WriteLine(p.Name + " is " + p.Age + " years old ");
80 // };
81 // PersonList.ForEach(p => Console.WriteLine(p.Name));
82 //});
83 #endregion
84
85 #region OrderBy排序 第二次用ThenBy排序
86 //ServiceInvoke.Invoke(() =>
87 //{
88 // Console.WriteLine("Initial Order:"); PersonList.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old "));//原来
89 // List<Person> pTempDefault = PersonList.OrderBy(p => p.Age).ToList(); Console.WriteLine("Default Order:");//默认由小到大---升序
90 // pTempDefault.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old "));//排序后
91
92 // //单条件降序
93 // List<Person> pTempDescending = PersonList.OrderByDescending(p => p.Age).ToList(); Console.WriteLine("Descending Order:");//降序
94 // pTempDescending.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old "));
95
96 // //多条件综合排序
97 // List<Person> pTempOrderBy_ThenByDescending = PersonList.OrderBy(p => p.Age).ThenByDescending(p => p.Id).ToList(); Console.WriteLine("OrderBy_ThenByDescending Order:");
98 // pTempOrderBy_ThenByDescending.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
99 //});
100 #endregion
101
102 #region Join 多个数据集(>=2)
103 //ServiceInvoke.Invoke(() =>
104 //{
105 // var joinedList = PersonList.Join(ChildList, p => p.Id, c => c.Id, (p, c) =>
106 // new { //匿名对象
107 // ParentID = p.Id,
108 // ChildID = c.Id,
109 // ParentName = p.Name,
110 // ChildName = c.Name
111 // }).ToList();
112 // joinedList.ForEach(j => Console.WriteLine(" ParentID: " + j.ParentID + " ChildID: " + j.ChildID + " ParentName: " + j.ParentName + " ChildName: " + j.ChildName));
113 //});
114 #endregion
115
116 #region GroupBy
117 //ServiceInvoke.Invoke(() =>
118 //{
119 // IEnumerable<IGrouping<string, Person>> groups = PersonList.GroupBy(p => p.Gender);
120 // IList<IGrouping<string, Person>> groupList = groups.ToList();
121 // foreach (var g in groupList)
122 // {
123 // //Key是分组依据的类型---Gender
124 // Console.WriteLine("Group:{0}", g.Key=="Male" ? "Male" : "Female");
125 // foreach (Person p in g)
126 // {
127 // Console.WriteLine(p.Name + " is " + p.Gender);
128 // }
129 // }
130 //});
131 #endregion
132
133 #region Skip与Take
134 //实现分页
135 //ServiceInvoke.Invoke(()=>
136 //{
137 // Console.WriteLine("First Page:");
138 // var firstPageData = GetPagedListByIndex(1,5);
139 // firstPageData.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
140 // Console.WriteLine("Second Page:");
141 // var secondPageData = GetPagedListByIndex(2, 5);
142 // secondPageData.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
143 // Console.WriteLine("Third Page:");
144 // var thirdPageData = GetPagedListByIndex(1, 5);
145 // thirdPageData.ForEach(p => Console.WriteLine(p.Name + " is " + p.Age + " years old " + " And his Id is " + p.Id));
146 //});
147 #endregion
148 #endregion
149
150 #region Linq
151
152 #region 基本查询
153 //ServiceInvoke.Invoke(()=>
154 //{
155 // var maleList = from p in PersonList
156 // where p.Gender == "Male"
157 // select p;
158 // maleList.ToList().ForEach(p => Console.WriteLine(p.Name + " is " + p.Gender));
159 //});
160 #endregion
161
162 #region 排序条件查询
163 //ServiceInvoke.Invoke(() =>
164 //{
165 // var orderList = from p in PersonList
166 // orderby p.Age descending//先按年龄排序
167 // orderby p.Name ascending//在上面的基础上按姓名排序
168 // select p;
169 // orderList.ToList().ForEach(p => Console.WriteLine(p.Name + " is " + p.Age));
170 //});
171 #endregion
172
173 #region 连接查询
174 //ServiceInvoke.Invoke(() =>
175 //{
176 // var joinedList = from p in PersonList
177 // join c in ChildList
178 // on p.Id equals c.Id
179 // select new
180 // {
181 // Person = p,
182 // Child = c
183 // };
184 // joinedList.ToList().ForEach(p => Console.WriteLine(" Person.Name is " + p.Person.Name + " Child.Name is " + p.Child.Name + " And Id is: "+ p.Child.Id));
185 //});
186 #endregion
187
188 #region 分组查询
189 ServiceInvoke.Invoke(() =>
190 {
191 var groupList = from p in PersonList
192 group p by p.Gender;
193 foreach (var g in groupList)
194 {
195 Console.WriteLine($"Group:{g.Key}");
196 foreach (var item in g)
197 {
198 Console.WriteLine(item.Name + " is "+ item.Gender);
199 }
200 }
201 });
202 #endregion
203
204 #endregion
205 }
206
207 static List<Person> GetPagedListByIndex(int pageIndex, int pageSize)
208 {
209 List<Person> dataList = PersonList;
210 return dataList.Skip((pageIndex - 1) * pageSize).Take(pageSize).ToList();
211 }
212 }
213 }
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