/**

 * 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 <= )

    {

        return ;

    }

    int i = ;

    int value = ;

    for (i=;i<len;i++)

    {

        value = value** + (str[i]/)* + str[i]%;

    }

    return value;

}