Creating Exe on the Fly

This is probably the most wonderful this I have explored in .net. What happens here is a user can actually make the EXE file on the fly. System.Runtime.Emit Namespace provides necessary class to do this.

After compiling this file and running it on the Console a new file is generated in your folder called TestAsm.exe. This Exe file print's a message "Hello World" on the Console.

Source Code

//RuntimeEmit.cs
using System;
using System.Runtime;
using System.Runtime.Emit;
Class RuntimeEmit
{
public static void Main(String [] args)
{
AppDomain ad = AppDomain.CurrentDomain;
AssemblyName am = new AssemblyName();
am.Name = "TestAsm";
AssemblyBuilder ab = ad.DefineDynamicAssembly(am,AssemblyBuilderAccess.Save);
ModuleBuilder mb = ab.DefineDynamicModule("testmod","TestAsm.exe");
TypeBuilder tb = mb.DefineType("mytype",TypeAttributes.Public);
MethodBuilder metb = tb.DefineMethod("hi",MethodAttributes.Public | MethodAttributes.Static,null,null);
mb.SetEntryPoint(metb);
ILGenerator il = metb.GetILGenerator();
il.EmitWriteLine("Hello World");
il.Emit(OpCodes.Ret);
tb.CreateType();
ab.Save("TestAsm.exe");
}
}

Save this file as RuntimeEmit.cs and Compile C:/>csc RuntimeEmit.cs and run this file C:\>RuntimeEmit

to run the Exe file generated C:\>TestAsm