C#转换ASCII码方法

        public byte[] GetASCII(byte a)
        {
byte b;
byte[] bs = new byte[2];
            b = (byte)(a & 0x0f);
if (b < 10)
                bs[1] = (byte)(0x30 + b);
else
                bs[1] = (byte)(0x37 + b);
            b = (byte)((a & 0xf0) >> 4);
if (b < 10)
                bs[0] = (byte)(0x30 + b);
else
                bs[0] = (byte)(0x37 + b);
return bs;
        }