Question

求高手帮我转成delphi

unsigned int16 UpdateCrc(unsigned char ch, unsigned int16 *lpwCrc)
{
ch = (ch^(unsigned char)((*lpwCrc) & 0x00FF));
ch = (ch^(ch<<4));

*lpwCrc = (*lpwCrc >> 8)^((unsigned int16)ch << 8)^((unsigned int16)ch<<3)^((unsigned int16)ch>>4);
return(*lpwCrc);
}

void ComputeCrc( char *Data, unsigned int8 Length,unsigned char *TransmitFirst, unsigned char *TransmitSecond)
{
unsigned char chBlock;
unsigned int16 wCrc;

wCrc = 0x6363; // ITU-V.41
do
{
chBlock = *Data++;
UpdateCrc(chBlock, &wCrc);
} while (--Length);

if (CRCType == CRC_B)
wCrc = ~wCrc; // ISO 3309
*TransmitFirst = (unsigned char) (wCrc & 0xFF);
*TransmitSecond = (unsigned char) ((wCrc >> 8) & 0xFF);
}

Answer 1

这是一个移位算法，主是没空写。
ch = (ch^(unsigned char)((*lpwCrc) & 0x00FF));
ch = (ch^(ch<<4));
是取CH后一个字节的值的意思，第一句是前高4个BIT位空，后一句是用低4个BIT位替换高4个BIT位，原位补0.
实现的方式很多，不一定要原样翻译