Creating method dynamically, and executing it

Question

Background:

I want to define few static methods in C# , and generate IL code as byte array, from one of these methods, selected at runt

Answer 1

This answer is a wee bit orthogonal - more about the problem than the technology involved.

You could use expression trees - they're nice to work with and have VS syntactic sugar.

For serialization you need this library (you'll need to compile it too): http://expressiontree.codeplex.com/ (This works with Silverlight 4 too, apparently.)

The limitation of expression trees is that they only support Lambda expressions - i.e. no blocks.

This isn't really a limitation because you can still define other lambda methods within a lambda and pass them to functional-programming helpers such as the Linq API.

I've included a simple extension method to show you how to go about adding other helper methods for functional stuff - the key point is that you need to include the assemblies containing the extensions in your serializer.

This code works:

using System;
using System.Linq;
using System.Linq.Expressions;
using ExpressionSerialization;
using System.Xml.Linq;
using System.Collections.Generic;
using System.Reflection;

namespace ExpressionSerializationTest
{
    public static class FunctionalExtensions
    {
        public static IEnumerable to(this int start, int end)
        {
            for (; start <= end; start++)
                yield return start;
        }
    }

    class Program
    {
        private static Expression> sumRange = 
            (x, y) => x.to(y).Sum();

        static void Main(string[] args)
        {
            const string fileName = "sumRange.bin";

            ExpressionSerializer serializer = new ExpressionSerializer(
                new TypeResolver(new[] { Assembly.GetExecutingAssembly() })
            );

            serializer.Serialize(sumRange).Save(fileName);

            Expression> deserializedSumRange =
                serializer.Deserialize>(
                    XElement.Load(fileName)
                );

            Func funcSumRange = 
                deserializedSumRange.Compile();

            Console.WriteLine(
                "Deserialized func returned: {0}", 
                funcSumRange(1, 4)
            );

            Console.ReadKey();
        }
    }
}