C# Convert Hiragana To Katakana By Unicode

hiragana2katakana

public string HiraganaToKatakana(string input)
{
    byte[] unicodes = Encoding.GetEncoding("Unicode").GetBytes(input);
    int i;
    for (i = 0; i < unicodes.Length; i += 2)                                     //Each 16 bits.
    {
        int _word = (unicodes[i + 1] << 8) | (unicodes[i] & 0xFF);              //Two byte make a word.
        if (_word >= 0x3041 && _word <= 0x30A0)                                 //In hiragana area?
        {
            _word += 0x60;                                                      //Add difference.
            unicodes[i + 1] = (byte)(_word >> 8);                               //Write back high byte.
            unicodes[i] = (byte)(_word & 0xFF);                                 //Write back low byte.
        }
    }
    return Encoding.GetEncoding("Unicode").GetString(unicodes);
}