/**  * 将unsigned char数组转换成long long数值 * {0x00 0x00 0x20 0x00}转换之后得到8192 *   * @param str 数组  * @param len str数组长度 * @returns 0 on error */LONGLONG PNGProcesser::readCharToLL(unsigned char* str, int len){    if (len <= 0)    {        return 0;    }    int i = 0;    int value = 0;    for (i=0;i