字符串转16进制

#include 
#include 
#include 

unsigned char StrTohex::strTohex(unsigned char* p_str, unsigned int str_len, unsigned char* p_data, unsigned int datlen)
{
	unsigned int i  = 0;

	if ((!p_data) || (!p_str) || (!str_len) || (2 * datlen < str_len)) 
		return false;	

	for (i = 0; i < str_len; i += 2) {
		ascToByte(p_str, p_data++);
		p_str += 2;
	}
	return true;	
}

unsigned char StrTohex::ascToByte(unsigned char* p_str, unsigned char* data)
{
	unsigned char tmphexdata = 0;

	if (!p_str) return false;
	if (!data) return false;

	tmphexdata = ascTohex(*p_str++);
	tmphexdata <<= 4;
	tmphexdata |= ascTohex(*p_str++);
	*data = tmphexdata;
	return true;
}

unsigned char StrTohex::ascTohex(unsigned char asc)
{
	switch (asc) {
		case '0': return 0x0;
		case '1': return 0x1;
		case '2': return 0x2;
		case '3': return 0x3;
		case '4': return 0x4;
		case '5': return 0x5;
		case '6': return 0x6;
		case '7': return 0x7;
		case '8': return 0x8;
		case '9': return 0x9;
		case 'a':
		case 'A': return 0xa;
		case 'b':
		case 'B': return 0xb;
		case 'c':
		case 'C': return 0xc;
		case 'd':
		case 'D': return 0xd;
		case 'e':
		case 'E': return 0xe;
		case 'f':
		case 'F': return 0xf;
		default : return 0xff;
	}
}