C# と VB.NET の質問掲示板

↓ たとえばこんなの?

using System;

namespace ConsoleApplication6
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] data = { "1_1.txt", "1_10.txt", "1_11.txt", "1_2.txt" };

            Array.Sort(data, (string x, string y) =>
            {
                // 文字長が短い方が小さい、文字長が同じならふつーに比較
                int t = x.Length.CompareTo(y.Length);
                return t != 0 ? t : x.CompareTo(y);
            });

            foreach (string item in data)
            {
                Console.WriteLine(item);
            }
            Console.ReadLine();
        }
    }
}

↑ わんだほー。

using System;

namespace ConsoleApplication6
{
    class Program
    {
        [System.Runtime.InteropServices.DllImport(
          "shlwapi.dll",
          CharSet = System.Runtime.InteropServices.CharSet.Unicode,
          ExactSpelling = true)]
        public static extern int StrCmpLogicalW(string x, string y); 

        static void Main(string[] args)
        {
            string[] data = { "1_1.txt", "1_10.txt", "1_11.txt", "1_2.txt" };
            Array.Sort(data, StrCmpLogicalW);
            Array.ForEach(data, Console.WriteLine);
            Console.ReadLine();
        }
    }
}