a.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;

namespace TrimStringTest
{
    /// <summary>
    /// テストデータ
    /// </summary>
    struct A
    {
        String a;
        public A(String a)
        {
            this.a = a;
        }
    };
    /// <summary>
    /// テストデータ
    /// </summary>
    class B
    {
        int b = 123;
        string c = " c   ";
        String d = " d";
    };
    /// <summary>
    /// テストデータ
    /// </summary>
    class C
    {
        A e = new A("   e");
        B[] f = new B[3] { new B(), new B(), new B() };
        B g = new B();
        string h = "  h";
        int i = 123;
    };

    public static class EnumeraleEx
    {
        public static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
        {
            foreach (var e in source)
            {
                action(e);
            }
        }
    }

    class Program
    {
        public static IEnumerable<Object> EnumTargetTypes(object obj)
        {
            return obj.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
                .SelectMany(f => f.FieldType != typeof(string) && typeof(IEnumerable).IsAssignableFrom(f.FieldType)
                    ? ((IEnumerable) f.GetValue(obj)).Cast<object>().SelectMany(EnumTargetTypes)
                    : new[] { f.GetValue(obj), }
                );
        }

        public static IEnumerable<T> EnumTargetTypes<T>(object obj)
        {
            return EnumTargetTypes(obj).OfType<T>();
        }

        public static void ActionTargetType<T>(object obj, Func<T, T> action)
        {
            obj.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)
                .ForEach(f =>
                {
                    if (f.FieldType != typeof(string) && typeof(IEnumerable).IsAssignableFrom(f.FieldType))
                    {
                        ((IEnumerable) f.GetValue(obj)).Cast<object>().ForEach(e => ActionTargetType<T>(e, action));
                    }
                    else if (typeof(T).IsAssignableFrom(f.FieldType))
                    {
                        var v = f.GetValue(obj);
                        f.SetValue(obj, action((T) v));
                    }
                });
        }

        /// <summary>
        /// Main()
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            C c = new C();
            foreach (String str in EnumTargetTypes<String>(c))
            {
                Console.WriteLine("{0}", str);
            }
            ActionTargetType<String>(c, (string member) => member = member.Trim());
            foreach (String str in EnumTargetTypes<String>(c))
            {
                Console.WriteLine("{0}", str);
            }
        }
    }
}