C# 秒數轉日期_由秒數獲得日期幾天幾小時_當前日期時間,轉換爲秒

///<summary>
///由秒數獲得日期幾天幾小時。。。
///</summary
///<param name="t">秒數</param>
///<param name="type">0：轉換後帶秒，1:轉換後不帶秒</param>
///<returns>幾天幾小時幾分幾秒</returns>
public static string parseTimeSeconds(int t, int type)
{
string r = "";
int day, hour, minute, second;
if (t >= 86400) //天,
{
day = Convert.ToInt16(t / 86400);
hour = Convert.ToInt16((t % 86400) / 3600);
minute = Convert.ToInt16((t % 86400 % 3600) / 60);
second = Convert.ToInt16(t % 86400 % 3600 % 60);
if (type == 0)
r = day + ("day") + hour + ("hour") + minute + ("minute") + second + ("second");
else
r = day + ("day") + hour + ("hour") + minute + ("minute");

}
else if (t >= 3600)//時,
{
hour = Convert.ToInt16(t / 3600);
minute = Convert.ToInt16((t % 3600) / 60);
second = Convert.ToInt16(t % 3600 % 60);
if (type == 0)
r = hour + ("hour") + minute + ("minute") + second + ("second");
else
r = hour + ("hour") + minute + ("minute");
}
else if (t >= 60)//分
{
minute = Convert.ToInt16(t / 60);
second = Convert.ToInt16(t % 60);
r = minute + ("minute") + second + ("second");
}
else
{
second = Convert.ToInt16(t);
r = second + ("second");
}
return r;
}

/// <summary>
/// 當前日期時間，轉換爲秒
/// </summary>
/// <returns>秒數</returns>
public static string xDateSeconds()
{
long xdateseconds = 0;
DateTime xdatenow = DateTime.UtcNow; //當前UTC時間


long xminute = 60; //一分種60秒
long xhour = 3600;
long xday = 86400;
long byear = 1970;//從1970-1-1 0：00：00開始到如今所過的秒
long[] xmonth = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
long[] xyear = { 365, 366 };
long num = 0;

xdateseconds += xdatenow.Second; //算秒
xdateseconds += xdatenow.Minute * xminute; //算分
xdateseconds += xdatenow.Hour * xhour; //算時
xdateseconds += (xdatenow.Day - 1) * xday; //算天

//算月(月換整天算)
if (DateTime.IsLeapYear(xdatenow.Year))
{
xdateseconds += (xmonth[xdatenow.Month - 1] + 1) * xday;
}
else
{
xdateseconds += (xmonth[xdatenow.Month - 1]) * xday;
}

//算年（年換整天算）
long lyear = xdatenow.Year - byear;

for (int i = 0; i < lyear; i++)
{
if (DateTime.IsLeapYear((int)byear + i))
{
num++;
}
}

xdateseconds += ((lyear - num) * xyear[0] + num * xyear[1]) * xday;

return xdateseconds.ToString();
}

/// <summary>
/// 秒數轉日期
/// </summary>
/// <param name="Value">秒數</param>
/// <returns>日期</returns>
public static DateTime GetGMTDateTime(int Value)
{
//秒數轉時間日期
//GMT時間從2000年1月1日開始，先把它做爲賦爲初值
long Year = 2000, Month = 1, Day = 1;
long Hour = 0, Min = 0, Sec = 0;
//臨時變量
long iYear = 0, iDay = 0;
long iHour = 0, iMin = 0, iSec = 0;
//計算文件建立的年份
iYear = Value / (365 * 24 * 60 * 60);
Year = Year + iYear;
//計算文件除建立全年份之外還有多少天
iDay = (Value % (365 * 24 * 60 * 60)) / (24 * 60 * 60);
//把閏年的年份數計算出來
int RInt = 0;
for (int i = 2000; i < Year; i++)
{
if ((i % 4) == 0)
RInt = RInt + 1;
}
//計算文件建立的時間(幾時)
iHour = ((Value % (365 * 24 * 60 * 60)) % (24 * 60 * 60)) / (60 * 60);
Hour = Hour + iHour;
//計算文件建立的時間(幾分)
iMin = (((Value % (365 * 24 * 60 * 60)) % (24 * 60 * 60)) % (60 * 60)) / 60;
Min = Min + iMin;
//計算文件建立的時間(幾秒)
iSec = (((Value % (365 * 24 * 60 * 60)) % (24 * 60 * 60)) % (60 * 60)) % 60;
Sec = Sec + iSec;
DateTime t = new DateTime((int)Year, (int)Month, (int)Day, (int)Hour, (int)Min, (int)Sec);
DateTime t1 = t.AddDays(iDay - RInt);
return t1;
}

把總秒數轉換成DataTime格式，注意時區，默認是格林威治時間GMT

DateTime dt = new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime().AddSeconds(info.lTime);
uploadtime.Text = string.Format("{0:F}", dt);