using System;

using System.Collections.Generic;

using System.Linq.Expressions;

using System.Reflection;

public class Program

{

    public static void Main()

    {

        List<string> numbers = new List<string>

        {

            "one",

            "twof",

        };

​

        // locate the property

        PropertyInfo indexer = numbers

            .GetType()

            .GetProperty(

                "Item",

                new Type[]

                {

                    typeof(int)

                });

​

        // ParameterExpression is used to map a value from the caller

        // to the lambda body

        ParameterExpression list = Expression.Parameter(

            numbers.GetType());

​

        ConstantExpression index = Expression.Constant(1);

​

        // define the body of the lambda

        MethodCallExpression body = Expression.Call(

            list,

            indexer.GetGetMethod(),

            new Expression[]

            {

                index

            });

​

        // Func<in T, out TResult>

​

        // first Type argument of Func definition will be Type of instance object

        // second Type argument of Func definition will be Type of return

​

        Expression<Func<List<string>, string>> lambda = Expression.Lambda<Func<List<string>, string>>(

​

            // this is going to be the function body/logic

            body,

​

            // this is the parameter list being passed in to the lambda body

​

            // have to use same ParameterExpression instances referenced in

            // expression body definition above to get them to map through Func call

            new ParameterExpression[]

            {

                list

            });

​

        // create the Func from the lambda

        Func<List<string>, string> func = lambda.Compile();

​

        // use Func to get value

        string number = func(numbers);

​

        Console.WriteLine(number);

    }

}