using Microsoft.CSharp;using System.CodeDom.Compiler;using System.Reflection;using System.Text;namespace System{    public static class CompileCSCAtRuntime    {        public static void HelloWorld()        {            string code = @"                using System;                namespace First                {                    public class Program                    {                        public static void Main()                        {                        " +                            "Console.WriteLine(\"Hello, world!\");"                          + @"                        }                    }                }            ";            CSharpCodeProvider provider = new CSharpCodeProvider();            CompilerParameters parameters = new CompilerParameters();            // Reference to System.Drawing library            parameters.ReferencedAssemblies.Add("System.Drawing.dll");            // True - memory generation, false - external file generation            parameters.GenerateInMemory = true;            // True - exe file generation, false - dll file generation            parameters.GenerateExecutable = true;            CompilerResults results = provider.CompileAssemblyFromSource(parameters, code);            if (results.Errors.HasErrors)            {                StringBuilder sb = new StringBuilder();                foreach (CompilerError error in results.Errors)                {                    sb.AppendLine(String.Format("Error ({0}): {1}", error.ErrorNumber, error.ErrorText));                }                throw new InvalidOperationException(sb.ToString());            }            Assembly assembly = results.CompiledAssembly;            Type program = assembly.GetType("First.Program");            MethodInfo main = program.GetMethod("Main");            main.Invoke(null, null);        }        public static void TestMeothds()        {            MethodInfo function = CreateFunction("x + 2 * y");            var betterFunction = (Func<double, double, double>)Delegate.CreateDelegate(typeof(Func<double, double, double>), function);            Func<double, double, double> lambda = (x, y) => x + 2 * y;            DateTime start;            DateTime stop;            double result;            int repetitions = 5000000;            start = DateTime.Now;            for (int i = 0; i < repetitions; i++)            {                result = OriginalFunction(2, 3);            }            stop = DateTime.Now;            Console.WriteLine("Original - time: {0} ms", (stop - start).TotalMilliseconds);            start = DateTime.Now;            for (int i = 0; i < repetitions; i++)            {                result = (double)function.Invoke(null, new object[] { 2, 3 });            }            stop = DateTime.Now;            Console.WriteLine("Reflection - time: {0} ms", (stop - start).TotalMilliseconds);            start = DateTime.Now;            for (int i = 0; i < repetitions; i++)            {                result = betterFunction(2, 3);            }            stop = DateTime.Now;            Console.WriteLine("Delegate - time: {0} ms", (stop - start).TotalMilliseconds);            start = DateTime.Now;            for (int i = 0; i < repetitions; i++)            {                result = lambda(2, 3);            }            stop = DateTime.Now;            Console.WriteLine("Lambda - time: {0} ms", (stop - start).TotalMilliseconds);        }        public static double OriginalFunction(double x, double y)        {            return x + 2 * y;        }        public static MethodInfo CreateFunction(string function)        {            string code = @"                using System;                            namespace UserFunctions                {                                    public class BinaryFunction                    {                                        public static double Function(double x, double y)                        {                            return func_xy;                        }                    }                }            ";            string finalCode = code.Replace("func_xy", function);            CSharpCodeProvider provider = new CSharpCodeProvider();            CompilerResults results = provider.CompileAssemblyFromSource(new CompilerParameters(), finalCode);            Type binaryFunction = results.CompiledAssembly.GetType("UserFunctions.BinaryFunction");            return binaryFunction.GetMethod("Function");        }    }}