using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using Microsoft.CSharp;

public class NotDynamicClass
{
    private readonly List<string> values = new List<string>();

    public void AddValue(string value)
    {
        values.Add(value);
    }

    public void ProcessValues()
    {
        foreach (var item in values)
        {
            Console.WriteLine(item);
        }
    }
}

class Program
{
    public static void Main()
    {
        var provider = CSharpCodeProvider.CreateProvider("c#");
        var options = new CompilerParameters();
        var assemblyContainingNotDynamicClass = Path.GetFileName(Assembly.GetExecutingAssembly().Location);
        options.ReferencedAssemblies.Add(assemblyContainingNotDynamicClass);
        var results = provider.CompileAssemblyFromSource(options, new[] 
        { 
@"public class DynamicClass
{
    public static void Main()
    {
        NotDynamicClass @class = new NotDynamicClass();
        @class.AddValue(""One"");
        @class.AddValue(""Two"");
        @class.ProcessValues();
    }
}"
        });
        if (results.Errors.Count > 0)
        {
            foreach (var error in results.Errors)
            {
                Console.WriteLine(error);
            }
        }
        else
        {
            var t = results.CompiledAssembly.GetType("DynamicClass");
            t.GetMethod("Main").Invoke(null, null);
        }
    }
}

using Roslyn.Compilers;
using Roslyn.Compilers.CSharp;
  
…
 
var text = @"class Calc { public static object Eval() { return 42; } }";
  
 var tree = SyntaxTree.ParseCompilationUnit(text);
 var compilation = Compilation.Create(
     "calc.dll",
     options: new CompilationOptions(assemblyKind: AssemblyKind.DynamicallyLinkedLibrary),
     syntaxTrees: new[] { tree },
     references: new[] { new AssemblyFileReference(typeof(object).Assembly.Location) });
  
 Assembly compiledAssembly;
using (var stream = new MemoryStream())
{
     EmitResult compileResult = compilation.Emit(stream);
     compiledAssembly = Assembly.Load(stream.GetBuffer());
}
  
 Type calc = compiledAssembly.GetType("Calc");
 MethodInfo eval = calc.GetMethod("Eval");
string answer = eval.Invoke(null, null).ToString();
  
 Assert.AreEqual("42", answer);