Simple working example of dynamically compiling a string of valid C# code and calling it

dynamiccompilation.cs

using System;

using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;

namespace dynamiccompilation
{
    class Program
    {
        static CompilerParameters CompilerParams = new CompilerParameters
        {
            GenerateInMemory = true,
            TreatWarningsAsErrors = false,
            GenerateExecutable = false
        };

        static string[] references = { "System.dll", "mscorlib.dll" };

        static CSharpCodeProvider provider = new CSharpCodeProvider();

        static void Main(string[] args)
        {
            CompilerParams.ReferencedAssemblies.AddRange(references);
            
            CompileAndRun(new string[] {
                "using System;" +
                "namespace dynamiccompilation" +
                "{" +
                "   public class DynamicExample" +
                "   {" +
                "       static public void Main()" +
                "       {" +
                "           System.Console.WriteLine(\"The time is now {0}.\", System.DateTime.Now);" +
                "       }" +
                "   }" +
                "}"});

            Console.ReadKey();
        }

        static void CompileAndRun(string[] code)
        {
            DateTime start = DateTime.Now;

            CompilerResults compile = provider.CompileAssemblyFromSource(CompilerParams, code);

            DateTime compilationFinished = DateTime.Now;
            
            if (compile.Errors.HasErrors)
            {
                foreach (CompilerError ce in compile.Errors)
                {
                    Console.WriteLine(ce.ToString());

                }
                Console.ReadKey();
                return;
            } else
            {
                Module module = compile.CompiledAssembly.GetModules()[0];

                module
                    .GetType("dynamiccompilation.DynamicExample")
                    .GetMethod("Main")
                    .Invoke(null, new object[] { });
            }

            DateTime executionFinished = DateTime.Now;
            Console.WriteLine($"Compile time: {compilationFinished - start}");
            Console.WriteLine($"Execution time: {executionFinished - compilationFinished}");
        }
        
    }
}