di injection

MySolution/ConsoleApp/Program.cs

@@ -1,4 +1,8 @@
-using Samples;
+using Samples.Calculate;
+using Samples.DI;
+using Samples.Event;
+using Samples.MessagePrinter;
+using Samples.StringLength;
 
 namespace ConsoleApp;
 class Program
@@ -15,14 +19,21 @@ class Program
 
         #region Callback
         
-        // StringLength.Sample();
+        // StringLengthSample.Sample();
 
         #endregion
 
 
         #region Event
             
-        EventSample.Sample();
+        // EventSample.Sample();
+
+        #endregion
+
+
+        #region Dependency Injection
+
+            DISample.Sample();
             
         #endregion
 

MySolution/ConsoleApp/Samples/CalculateSample.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Samples
+namespace Samples.Calculate
 {
     class CalculateSample
     {

MySolution/ConsoleApp/Samples/DISample.cs

@@ -0,0 +1,58 @@
+namespace Samples.DI
+{
+    class DISample
+    {
+        public static void Sample()
+        {
+            DIContainer container = new DIContainer();
+            container.Register<IService, Service>();
+            
+            Client client = new Client(container.Resolve<IService>());
+            client.Run();
+        }
+    }
+
+    public interface IService
+    {
+        void DoSomething();
+    }
+
+    public class Service : IService
+    {
+        public void DoSomething()
+        {
+            Console.WriteLine("Service is doing something...");
+        }
+    }
+
+    public class Client
+    {
+        private readonly IService _service;
+
+        public Client(IService service)
+        {
+            _service = service;
+        }
+
+        public void Run()
+        {
+            _service.DoSomething();
+        }
+    }
+
+    public class DIContainer
+    {
+        private readonly Dictionary<Type, Type> _typemappings = new Dictionary<Type, Type>();
+
+        public void Register<TInterface, TImplementation>()
+        {
+            _typemappings[typeof(TInterface)] = typeof(TImplementation);
+        }
+
+        public TInterface Resolve<TInterface>()
+        {
+            Type implementationType = _typemappings[typeof(TInterface)];
+            return (TInterface)Activator.CreateInstance(implementationType);
+        }
+    }
+}

MySolution/ConsoleApp/Samples/EventSample.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Samples
+namespace Samples.Event
 {
     public delegate void CustomEventHandler(object sender, EventArgs e);
 

MySolution/ConsoleApp/Samples/MessagePrinterSample.cs

@@ -2,7 +2,7 @@ using System;
 using System.Diagnostics;
 using System.Threading.Tasks;
 
-namespace Samples
+namespace Samples.MessagePrinter
 {
     class MessagePrinterSample
     {

MySolution/ConsoleApp/Samples/StringLengthSample.cs

@@ -1,8 +1,8 @@
 using System;
 
-namespace Samples
+namespace Samples.StringLength
 {
-    class StringLength
+    class StringLengthSample
     {
         public static void Sample()
         {