添加Lesson15

C#进阶/Lesson15_lambad表达式练习/Lesson15_lambda表达式练习.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

C#进阶/Lesson15_lambad表达式练习/Program.cs

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+namespace Lesson15_lambda表达式练习
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            a1()();
+            a2()();
+        }
+        
+        public static Action a1()
+        {
+            Action action = null;
+            for (int i = 1; i <= 10; i++)
+            {
+                int index = i;
+                action += delegate()
+                {
+                    Console.WriteLine(index);
+                };
+            }
+            return action;
+        }
+        public static Action a2()
+        {
+            Action action = null;
+            for (int i = 1; i <= 10; i++)
+            {
+                int index = i;
+                action += () => Show(index);
+            }
+            return action;
+        }
+        public static Action a3()
+        {
+            Action action = null;
+            for (int i = 1; i <= 10; i++)
+            {
+                int index = i;
+                action += () => Show(index);
+            }
+            return action;
+        }
+        static void Show(int x)
+        {
+            Console.WriteLine(x);
+        }
+    }
+
+}