16进制字符串 相互转换

将16进制字符串“313233”转换为字符串“123”

void HexStrToBuf(uint8_t *Buf, char *Str, uint16_t StrLen)
{
    uint8_t Hex;
    uint16_t i, N = 0;

    if(StrLen > 1000 || StrLen % 2 != 0)return;//必要的保护

    for(i = 0; i < StrLen ;)
    {
        if(Str[i] >= '0' && Str[i] <= '9')Hex = (Str[i] - 48) << 4;
        else if(Str[i] >= 'A' && Str[i] <= 'F')Hex = (Str[i] - 55) << 4;
        else if(Str[i] >= 'a' && Str[i] <= 'f')Hex = (Str[i] - 87) << 4;

        i++;//防止死循环

        if(Str[i] >= '0' && Str[i] <= '9')Hex += (Str[i] - 48);
        else if(Str[i] >= 'A' && Str[i] <= 'F')Hex += (Str[i] - 55);
        else if(Str[i] >= 'a