学步园

#include <iostream>
#include <sstream>
#include <cstdlib>

using namespace std;

void string_to_hex(ostringstream& oss, string s)
{
    oss.flags(ios::hex | ios::showbase | ios::uppercase);
    for(size_t i=0; i<s.length(); ++i)
        oss << static_cast<unsigned long>(s[i]) << ' ';
}

string hex_to_string(istringstream& iss)
{
    string re;
    string tmp;
    unsigned long n;

    while(iss>>tmp) {
        n = strtoul(tmp.c_str(), 0, 0);
        re.push_back(static_cast<char>(n));
    }
    return re;
}

int main ( )
{
    cout << "你好，世界！\n";

    ostringstream oss(ostringstream::out);
    string_to_hex(oss, "你好，世界！");
    cout << oss.str() << endl;

    istringstream iss(oss.str());
    cout << hex_to_string(iss);
    return 0;
}

转载：http://bbs.csdn.net/topics/310241436