c++获取当前时间并格式化时间

梦里梦外; 2023-09-26 19:38 153阅读 0赞

## 使用C标准库 ##

相关日期、时间函数见[C/C++ 日期 & 时间 函数总结][C_C_ _ _ _]

#include <stdio.h>      /* printf, scanf */
    #include <time.h> 
    using namespace std;
    #pragma warning( disable : 4996 )
    #include <iostream>
    int main()
    {
        time_t rawtime;
        struct tm* timeinfo;
        char buffer[80];
        time(&rawtime);
        timeinfo = localtime(&rawtime);
         printf("当前时间: %s", asctime(timeinfo));
        //格式化时间
        strftime(buffer, 80, "%Y-%m-%d %H:%M:%S", timeinfo);
        std::cout <<"24小时制时间 " << buffer << std::endl;
        //转换为12小时制
        strftime(buffer, 80, "%Y-%m-%d %I:%M:%S", timeinfo);
        std::cout <<"12小时制日期时间 " << buffer << std::endl;
        strftime(buffer, 80, "%I:%M:%S %p", timeinfo);
        std::cout << "12小时制时间 " << buffer << std::endl;
        return 0;
    }

![1e0d1e5524b943dea96c7363fa04df47.png][]

也可以自己写24小时制转12小时制时间函数，如下：

/**
     * 转换为12小时格式
     * @param str 24小时制时间字符串 如 08:59:07 或者 20:59:07
     * @return 12小时制的时间格式
     */
    string convert_12hour(string str) {
    	string time;
    	int h1 = (int) str[0] - '0';
    	int h2 = (int) str[1] - '0';
    	int hh = h1 * 10 + h2;
    	//找到扩展名
    	string Meridien;
    	if (hh < 12) {
    		Meridien = "AM";
    	} else
    		Meridien = "PM";
    	hh %= 12;
    	if (hh == 12) {
    		time += "12";
    		for (int i = 2; i < 8; ++i) {
    			cout << str[i];
    		}
    	} else if (hh == 24) {
    		time = "00";
    		for (int i = 2; i < 8; ++i) {
    			time += str[i];
    		}
    	} else {
    		string h = to_string(hh);
    		time += h;
    		for (int i = 2; i < 8; ++i) {
    			time += str[i];
    		}
    	}
    	return time += " " + Meridien;
    }

## windows API ##

#include <stdio.h>      /* printf, scanf */
    #include <time.h> 
    using namespace std;
    #pragma warning( disable : 4996 )
    #include <iostream> /*cout*/
    
    #include <windows.h> 
    //可以精确到毫秒
    int main()
    {
        SYSTEMTIME sys;
        GetLocalTime(&sys);
        printf("%4d/%02d/%02d %02d:%02d:%02d.%03d 星期%1d\n", sys.wYear, sys.wMonth, sys.wDay, sys.wHour, sys.wMinute, sys.wSecond, sys.wMilliseconds, sys.wDayOfWeek);
        char buf[128];
        //重新赋值给字符串
        sprintf(buf, "%4d-%02d-%02d %02d:%02d:%02d.%03d 星期%1d\n", sys.wYear, sys.wMonth, sys.wDay, sys.wHour, sys.wMinute, sys.wSecond, sys.wMilliseconds, sys.wDayOfWeek);
        cout << "重新赋值给字符串" << buf << endl;
        
        return 0;
    }

![071516082e094b978b1e716c03fb6731.png][]

## 利用系统函数,还能改动系统时间 ##

#include <stdio.h>      /* printf, scanf */
    
    using namespace std;
    #pragma warning( disable : 4996 )
    #include <iostream> /*cout*/
    #include<string>
    #include <ctime> 
    
    int main()
    {
        system("time");
        return 0;
    }

![f98c14da2bd2434dbc61f9d680120389.png][]

[C_C_ _ _ _]: https://blog.csdn.net/jg_csdn/article/details/129879882?spm=1001.2014.3001.5501
[1e0d1e5524b943dea96c7363fa04df47.png]: https://img-blog.csdnimg.cn/1e0d1e5524b943dea96c7363fa04df47.png
[071516082e094b978b1e716c03fb6731.png]: https://img-blog.csdnimg.cn/071516082e094b978b1e716c03fb6731.png
[f98c14da2bd2434dbc61f9d680120389.png]: https://img-blog.csdnimg.cn/f98c14da2bd2434dbc61f9d680120389.png