高性能的字节数组与十六进制字符串互相转换

/* the following methods have high performance and come from: http://stackoverflow.com/a/24343727/2753545 */

private static readonly uint[] _lookup32 = CreateLookup32();

private static uint[] CreateLookup32()
{
    var result = new uint[256];
    for (int i = 0; i < 256; i++)
    {
        string s = i.ToString("X2");
        result[i] = ((uint)s[0]) + ((uint)s[1] << 16);
    }
    return result;
}

public static string ByteArrayToHexViaLookup32(byte[] bytes)
{
    uint[] lookup32 = _lookup32;
    char[] result = new char[bytes.Length * 2];
    for (int i = 0; i < bytes.Length; i++)
    {
        uint val = lookup32[bytes[i]];
        result[2 * i] = (char)val;
        result[2 * i + 1] = (char)(val >> 16);
    }
    return new string(result);
}

// this method is from http://stackoverflow.com/a/17923942/2753545
public static byte[] HexToByteUsingByteManipulation(string s)
{
    byte[] bytes = new byte[s.Length / 2];
    for (int i = 0; i < bytes.Length; i++)
    {
        int hi = s[i * 2] - 65;
        hi = hi + 10 + ((hi >> 31) & 7);

        int lo = s[i * 2 + 1] - 65;
        lo = lo + 10 + ((lo >> 31) & 7) & 0x0f;

        bytes[i] = (byte)(lo | hi << 4);
    }
    return bytes;
}