IVS文字かどうか調べる

TestIVS.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Globalization;
using System.Windows.Forms;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            
            var testString = "渡\u908A\uDB40\uDD07さん";
            var ivs = new TestIVS();
            for (int i = 0; i < testString.Length; i++)
            {
                Console.WriteLine(ivs.IsIvsChar(testString, i));
            }
            MessageBox.Show(testString);
            Console.Read();
        }
    }

    public class TestIVS
    {
        //日本の漢字の異字体セレクタはVariation Selector Supplementの範囲だけ使用される
        private char VariationSelectorSupplementHi = '\uDB40';
        private char VariationSelectorSupplementLoStart = '\uDD00';
        private char VariationSelectorSupplementLoEnd = '\uDDEF';
        //それ以外だと以下が使われている可能性がある
        private char VariationSelectorStart = '\uFE00';
        private char VariationSelectorEnd = '\uFE0F';
        //モンゴル文字用
        private char MongolianFreeVariationSelectorOne = '\u180B';
        private char MongolianFreeVariationSelectorThree = '\u180d';



        public bool IsIvsChar(string text, int index)
        {
            char buf = text[index];
            if (buf == VariationSelectorSupplementHi
                || (VariationSelectorSupplementLoStart <= buf && buf <= VariationSelectorSupplementLoEnd)
                ||(VariationSelectorStart <= buf && buf <= VariationSelectorEnd)
                || (MongolianFreeVariationSelectorOne <= buf && buf <= MongolianFreeVariationSelectorThree))
            {
                return true;
            }
            return false;
        }


    }
}

/**
 * http://www.fileformat.info/info/unicode/block/variation_selectors_supplement/list.htm
 * http://www.fileformat.info/info/unicode/block/variation_selectors/index.htm
 * http://ja.wikipedia.org/wiki/%E7%95%B0%E4%BD%93%E5%AD%97%E3%82%BB%E3%83%AC%E3%82%AF%E3%82%BF
 * 
 * 
 * 
 * 
 * 
 * */