using System;

public class Program

{

    public static void Main()

    {

           using (Microsoft.CSharp.CSharpCodeProvider foo =

           new Microsoft.CSharp.CSharpCodeProvider())

            {

                var res = foo.CompileAssemblyFromSource(

                    new System.CodeDom.Compiler.CompilerParameters()

                    {

                        GenerateInMemory = true

                    },

                    "public class FooClass { public string Execute() { return \"output!\";}}"

                );

​

                var type = res.CompiledAssembly.GetType("FooClass");

​

                var obj = Activator.CreateInstance(type);

​

                var output = type.GetMethod("Execute").Invoke(obj, new object[] { });

​

                Console.WriteLine(output);

    }

}

}