类型转换的实现代码(C++)

byte CFormat_Input::ASCII_Hex_to_Byte(char *ascii_hex)
{
 int i;
 char cTemp;
 byte byReturn;

 byReturn=0;
 for (i=0; i < 2; i++)
 {
  cTemp=ascii_hex[i];
  if ( cTemp == 0x00 )
   break;
  byReturn=byReturn<<4;
  if ( (cTemp >= '0')&&(cTemp <='9') )
   byReturn+=cTemp-'0';
  else
  {
   cTemp|=0x20;
   if ( (cTemp >= 'a')&&(cTemp <='f') )
    byReturn+=cTemp-'a'+0x0a;
  }
 }

 return byReturn;
}

 

void CFormat_Input::Hex_2_Bin_format(char *szDes, byte bySrc)
{
 char *Hex_2_Bin_array[]={
       "0000",
       "0001",
       "0010",
       "0011",
       "0100",
       "0101",
       "0110",
       "0111",
       "1000",
       "1001",
       "1010",
       "1011",
       "1100",
       "1101",
       "1110",
       "1111",
       };

 sprintf(&szDes[0], "%s", Hex_2_Bin_array[(int)bySrc/0x10]);
 sprintf(&szDes[4], "%s", Hex_2_Bin_array[(int)bySrc%0x10]);
}

unsigned long CFormat_Input::ASCII_To_long(byte *bySrc, int nInput_length, byte bySwitch)
{
 int i;
 unsigned long ulResult;

 if (nInput_length >= 5)
  return 0x00;

 ulResult=0;

 switch (bySwitch)
 {
 case 0x00:
  {
   for (i=0; i < nInput_length; i++)
   {
    ulResult=(ulResult<<8)+bySrc[i];
   }

   break;
  }
 case 0x01:
  {
   for (i=0; i < nInput_length; i++)
   {
    ulResult=(ulResult<<8)+bySrc[nInput_length-i-1];
   }

   break;
  }
 }

 return ulResult;
}