从char*数组中读取"整数"大小的字节.

int getIntFromCharArray(char* arr, bool isLittleEndian) {
    int result = 0;
    if (isLittleEndian) {
        for (int i = 0; i< sizeof(int); i++) {
            result |= (unsigned char)arr[i] << (i * 8);
        }
    } else {
        for (int i = 0; i< sizeof(int); i++) {
            result |= (unsigned char)arr[i] << ((sizeof(int) - i - 1) * 8);
        }
    }
    return result;
}