Unix时间戳与C# DateTime时间类型、C语言互换 1970-01-01 00:00:00

和同事的下位机交互的时候，需要使用到时间转换，

刚好找到这篇文章，用C语言实现的话，还挺麻烦的

下面给出C#和C的源码

注：C# 转自 http://www.cnblogs.com/hanhualangzi/archive/2012/02/10/2345952.html

C源码是同事给我的；

C#：

 1 dangranusing System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 
 5 namespace WWFramework.DateTimes
 6 {
 7     /// <summary>
 8     /// 时间相关函数
 9     /// </summary>
10     public static class Function
11     {
12         /// <summary>
13         /// 将Unix时间戳转换为DateTime类型时间
14         /// </summary>
15         /// <param name="d">double 型数字</param>
16         /// <returns>DateTime</returns>
17         public static System.DateTime ConvertIntDateTime(double d)
18         {
19             System.DateTime time = System.DateTime.MinValue;
20             System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
21             time = startTime.AddSeconds(d);
22             return time;
23         }
24 
25         /// <summary>
26         /// 将c# DateTime时间格式转换为Unix时间戳格式
27         /// </summary>
28         /// <param name="time">时间</param>
29         /// <returns>double</returns>
30         public static double ConvertDateTimeInt(System.DateTime time)
31         {
32             double intResult = 0;
33             System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
34             intResult = (time - startTime).TotalSeconds;
35             return intResult;
36         }
37     }
38 }

C源码：

  1 struct tm
  2 {
  3         uint32     tm_sec;         /* seconds after the minute - [0, 59]   */
  4         uint32     tm_min;         /* minutes after the hour - [0, 59]     */
  5         uint32     tm_hour;        /* hours since midnight - [0, 23]       */
  6         uint32     tm_mday;        /* day of the month - [1, 31]           */
  7         uint32     tm_mon;         /* months since January - [0, 11]       */
  8         uint32     tm_year;        /* year since 1900                      */
  9         uint32     tm_wday;        /* days since Sunday - [0, 6]           */
 10         uint32     tm_yday;        /* days since January 1 - [0, 365]      */
 11         uint32     tm_isdst;       /* Daylight Saving Time flag            */
 12 };
 13 tm  time;
 14 void localtime_h(uint32 time, struct tm *ret_time)
 15 {
 16     static const char month_days[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 17     static const char leap_year[4] = {0, 0, 1, 0};
 18     uint32 j = 0;
 19     uint32 day_count = 0;
 20     uint32 i = 0;
 21     uint32 leave_for_fouryear = 0;
 22     uint32 four_year_count = 0;
 23     uint32 temp_value = 0;
 24     uint32 leave_for_year_days;
 25     uint32 leave_for_month_days;
 26     //time=time-28800;
 27     ret_time->tm_sec = 0;
 28     ret_time->tm_min = 0;
 29     ret_time->tm_hour = 0;
 30     ret_time->tm_wday = 0;
 31     ret_time->tm_year = 0;
 32     ret_time->tm_mday = 0;
 33     ret_time->tm_mon = 0;
 34     ret_time->tm_sec = time % 60;
 35     temp_value = time / 60;
 36     ret_time->tm_min = temp_value % 60;
 37     temp_value /= 60; 
 38     temp_value += 8;
 39     ret_time->tm_hour = temp_value % 24;
 40     temp_value /= 24;
 41     ret_time->tm_wday = (temp_value + 4) % 7;
 42     four_year_count = temp_value / (365 * 4 + 1);
 43     leave_for_fouryear = temp_value % (365 * 4 + 1);
 44     leave_for_year_days = leave_for_fouryear; 
 45    for (i = 0; i < 4; i++)
 46    {        
 47         day_count = leap_year[i] ? 366 : 365;
 48         
 49         if (leave_for_year_days <= day_count)
 50         {
 51             break;
 52         }
 53         else
 54         {
 55             leave_for_year_days -= day_count;
 56         }
 57    }
 58     ret_time->tm_year = four_year_count * 4 + i ;
 59     ret_time->tm_yday = leave_for_year_days;
 60     leave_for_month_days = leave_for_year_days;
 61    for (j = 0; j < 12; j++)
 62    {
 63        if (((leap_year[i])) && (j == 1))
 64        {
 65            if (leave_for_month_days <= 29)
 66            {
 67                break;
 68            }
 69            else if (leave_for_month_days == 29)
 70            {
 71                i++;
 72                leave_for_month_days = 0;
 73                break;
 74            }
 75            else
 76            {
 77                leave_for_month_days -= 29;
 78            }
 79            
 80            continue;    
 81        }
 82                
 83        if (leave_for_month_days < month_days[j])
 84        {
 85            break;
 86        }
 87        else if(leave_for_month_days == month_days[j]){
 88            i++;
 89            leave_for_month_days = 0;
 90            break;
 91        }
 92        else
 93        {
 94            leave_for_month_days -= month_days[j];
 95        }                
 96    }
 97    ret_time->tm_mday = leave_for_month_days + 1;
 98    ret_time->tm_mon = j;
 99 }
100 void ConvSecTimeToCalendar(struct tm *t_tm,uint32 t)
101 {
102     t=(t>=28800)?(t-28800):t;
103     localtime_h(t,t_tm);
104     t_tm->tm_year +=1970;
105     t_tm->tm_mon +=1;
106 }