看到前面有人要，我在这里贴一个函数。
int HexToBin(char *sHex ,char *pBuf ,int ilen)
{
unsigned char sHexStr[3] ;
int iErr=0 ;
memset(sHexStr,0x0,3) ;
for( int i=0;i<ilen;i++)
{
memcpy(sHexStr,&sHex[i*2],2) ;
if( sHexStr[0]>='0' && sHexStr[0]<='9' )
sHexStr[0]=sHexStr[0]-'0' ;
else
if( sHexStr[0]>='A' && sHexStr[0]<='F' )
sHexStr[0]=sHexStr[0]-'A'+10 ;
else
{
sHexStr[0] = 0 ;
iErr++ ;
}
if( sHexStr[1]>='0' && sHexStr[1]<='9' )
sHexStr[1]=sHexStr[1]-'0' ;
else
if( sHexStr[1]>='A' && sHexStr[1]<='F' )
sHexStr[1]=sHexStr[1]-'A'+10 ;
else
{
sHexStr[1] = 0 ;
iErr++ ;
}
pBuf[i] = sHexStr[0]*16 + sHexStr[1] ;
}
return iErr ;
}