Add Sample HelloWorld program

Author: devlights

TryCSharp.DotNetCore2.Tutorial/HelloWorld.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace TryCSharp.DotNetCore2.Tutorial
+{
+    internal class HelloWorld : IExecutable
+    {
+        public void Execute()
+        {
+            Console.WriteLine("Hello world");
+        }
+    }
+}

TryCSharp.DotNetCore2.Tutorial/IExecutable.cs

@@ -0,0 +1,7 @@
+namespace TryCSharp.DotNetCore2.Tutorial
+{
+    internal interface IExecutable
+    {
+        void Execute();
+    }
+}

TryCSharp.DotNetCore2.Tutorial/Program.cs

@@ -2,11 +2,47 @@
 
 namespace TryCSharp.DotNetCore2.Tutorial
 {
-    class Program
+    internal class Program
     {
-        static void Main(string[] args)
+        private static void Main(string[] args)
         {
-            Console.WriteLine("Hello World!");
+            var me = new Program();
+            me.Execute();            
+        }
+
+        private void Execute()
+        {
+            var input = Console.ReadLine();
+            if (string.IsNullOrWhiteSpace(input))
+            {
+                Console.WriteLine("please enter class name. exit....");
+                return;
+            }
+
+            var fullTypeName = string.Format("TryCSharp.DotNetCore2.Tutorial.{0}", input);
+            var type = Type.GetType(fullTypeName);
+            if (type == null)
+            {
+                Console.WriteLine("[ERROR] target type does not found. exit....");
+                return;
+            }
+            
+            var instance = Activator.CreateInstance(type);
+            if (instance == null)
+            {
+                Console.WriteLine("[ERROR] error has occured exit....");
+                return;
+            }
+
+            if (!(instance is IExecutable executable))
+            {
+                Console.WriteLine("[ERROR] can't cast to IExecutable. exit...");
+                return;
+            }
+            
+            executable.Execute();
+
+            Console.WriteLine("exit");
         }
     }
 }

TryCSharp.DotNetCore2.Tutorial/TryCSharp.DotNetCore2.Tutorial.csproj

@@ -1,8 +1,6 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp2.0</TargetFramework>
   </PropertyGroup>
-
-</Project>
+</Project>