using System;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Text;

namespace Code_zur_Laufzeit_erzeugen
{
 class Program
 {
  static void Main(string[] args)
  {
   Console.Write("Enter text -> ");
   string textInput = Console.ReadLine();

   Assembly assembly = CompileCode(textInput);
   object o = assembly.CreateInstance("gfoidl.Code.Test");
   Type t = o.GetType();
   MethodInfo mi = t.GetMethod("Ergebnis");
   object result = mi.Invoke(o, new object[] { textInput });
   Console.WriteLine(result);

   Console.ReadKey();
  }
  //---------------------------------------------------------------------
  public static Assembly CompileCode(string inputCode)
  {
   CodeDomProvider provider = CodeDomProvider.CreateProvider("CSharp");

   CompilerParameters cp = new CompilerParameters();
   cp.ReferencedAssemblies.Add("system.dll");
   cp.CompilerOptions = "/t:library";
   cp.GenerateInMemory = true;

   StringBuilder sb = new StringBuilder();
   sb.AppendLine(@"using System;");
   sb.AppendLine(@"namespace gfoidl.Code{");
   sb.AppendLine(@"public class Test{");
   sb.AppendLine(@"public string Ergebnis(string input){");
   sb.AppendLine(@"return input + ""\t"" + input;");
   sb.AppendLine(@"}}}");

   CompilerResults cr =
    provider.CompileAssemblyFromSource(cp, sb.ToString());

   if (cr.Errors.Count > 0)
   {
    Console.WriteLine(cr.Errors[0].ErrorText);
    return null;
   }

   return cr.CompiledAssembly;
  }
 }
}