Illustrates runtime type creation : Type : Reflection C# Source Code

    

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example17_7 illustrates runtime type creation
*/

using System;
using System.Reflection;
using System.Reflection.Emit;

public class Example17_7 
{

    public static void Main() 
    {
        // get the current appdomain
        AppDomain ad = AppDomain.CurrentDomain;

        // create a new dynamic assembly
        AssemblyName an = new AssemblyName();
        an.Name = "DynamicRandomAssembly";
        AssemblyBuilder ab = ad.DefineDynamicAssembly(
         an, AssemblyBuilderAccess.Run);

        // create a new module to hold code in the assembly
        ModuleBuilder mb = ab.DefineDynamicModule("RandomModule");

        // create a type in the module
        TypeBuilder tb = mb.DefineType(
         "DynamicRandomClass",TypeAttributes.Public);

        // create a method of the type
        Type returntype = typeof(int);
        Type[] paramstype = new Type[0];
        MethodBuilder methb=tb.DefineMethod("DynamicRandomMethod", 
         MethodAttributes.Public, returntype, paramstype);

        // generate the MSIL
        ILGenerator gen = methb.GetILGenerator();
        gen.Emit(OpCodes.Ldc_I4, 1);
        gen.Emit(OpCodes.Ret);

        // finish creating the type and make it available
        Type t = tb.CreateType();

        // create an instance of the new type
        Object o = Activator.CreateInstance(t);
        // create an empty arguments array
        Object[] aa = new Object[0];
        // get the method and invoke it
        MethodInfo m = t.GetMethod("DynamicRandomMethod");
        int i = (int) m.Invoke(o, aa);
        Console.WriteLine("Method {0} in Class {1} returned {2}",
            m, t, i);

    }
}
//=============================================================
using System;

public class DynamicRandomClass
{
    public int DynamicRandomMethod()
    {
        return 1;
    }
}