c# create dll runtime
using System.CodeDom.Compiler;
using System.Diagnostics;
using Microsoft.CSharp;
CSharpCodeProvider codeProvider = new CSharpCodeProvider();
ICodeCompiler icc = codeProvider.CreateCompiler();
System.CodeDom.Compiler.CompilerParameters parameters = new CompilerParameters();
parameters.GenerateExecutable = false;
parameters.OutputAssembly = "AutoGen.dll";
CompilerResults results = icc.CompileAssemblyFromSource(parameters, yourCodeAsString);