c++ 字符数组-print and 写入文件

 char buffer[22][8] = { 0 };
method1:
为了打印出unsigned char数据所对应的数值，可以将其强制转换成int类型，并做打印输出。
std::cout << "buffer[22][0]: " << std::hex << (int)buffer[22][0] << std::endl;
 
method2:
printf("buffer[0]: --- %x --- %d\n", (unsigned char)buffer[i][0], i+1);

//#include <fstream>
std::ofstream in;//buffer data to be writen...
std::ofstream out;//can data...

in.open("in.txt", ios::trunc);

out.open("out.txt", ios::trunc);

for (int k = 0; k < 8; k++)
{
out << std::hex << (int)frame.data[k] << "\t";
}
out << "\n";

//close file.
in.close();
out.close();