C++格式化时间

c++格式化时间

方法一(作者使用的方法)、strftime()函数 

#include <ctime>
#include <string>
#include <sstream>

std::string stime;
std::stringstream strtime;
std::time_t currenttime = std::time(0);	
char tAll[255];
std::strftime(tAll, sizeof(tAll), "%Y-%m-%d-%H-%M-%S", std::localtime(&currenttime));
strtime << tAll;
stime = strtime.str();

注意：对于localtime()函数windows平台会报错。

'localtime': This function or variable may be unsafe. Consider using localtime_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

需要使用微软提供的 localtime_s 或者 添加消除警告的宏。

这里使用vs2015，在IDE里添加里消除警告的宏  _CRT_SECURE_NO_DEPRECATE

项目->属性->配置属性->C/C++ -> 预处理器 -> 预处理器定义

Project->Properties->Configration Properties->C/C++->Preprocessor->Preprocessor Definitions

参照：

http://stackoverflow.com/questions/10289017/how-to-format-date-and-time-string-in-c

http://stackoverflow.com/questions/16357999/current-date-and-time-as-string

http://blog.youkuaiyun.com/shellching/article/details/8114266

http://www.cnblogs.com/gb2013/archive/2013/03/05/SecurityEnhancementsInTheCRT.html

http://stackoverflow.com/questions/14386923/localtime-vs-localtime-s-and-appropriate-input-arguments

方法二、c++11 的put_time()函数

来源：http://en.cppreference.com/w/cpp/io/manip/put_time

#include <iostream>
#include <iomanip>
#include <ctime>
 
int main()
{
    std::time_t t = std::time(nullptr);
    std::tm tm = *std::localtime(&t);
    std::cout.imbue(std::locale("ru_RU.utf8"));
    std::cout << "ru_RU: " << std::put_time(&tm, "%c %Z") << '\n'; // %Y-%m-%d %H:%M:%S
    std::cout.imbue(std::locale("ja_JP.utf8"));
    std::cout << "ja_JP: " << std::put_time(&tm, "%c %Z") << '\n';
}

方法三、time_put()函数

来源： https://www.safaribooksonline.com/library/view/c-cookbook/0596007612/ch05s03.html

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <string>
#include <stdexcept>
#include <iterator>
#include <sstream>

using namespace std;

ostream& formatDateTime(ostream& out, const tm& t, const char* fmt) {
  const time_put<char>& dateWriter = use_facet<time_put<char> >(out.getloc());
  int n = strlen(fmt);
  if (dateWriter.put(out, out, ' ', &t, fmt, fmt + n).failed()) {
    throw runtime_error("failure to format date time");
  }
  return out;
}

string dateTimeToString(const tm& t, const char* format) {
  stringstream s;
  formatDateTime(s, t, format);
  return s.str();
}

tm now() {
  time_t now = time(0);
  return *localtime(&now);
}

int main()
{
  try {
    string s = dateTimeToString(now(), "%A %B, %d %Y %I:%M%p");
    cout << s << endl;
    s = dateTimeToString(now(), "%Y-%m-%d %H:%M:%S");
    cout << s << endl;
  }
  catch(...) {
    cerr << "failed to format date time" << endl;
    return EXIT_FAILURE;
  }
  return EXIT_SUCCESS;
}