DatetimeHelper类的编写

公共类 DAtaTimeHelper类的编写

public class Appointment
{
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
}
public static class DateTimeExtensions
{
public static DateTime FromTodayGetSundayDay(this DateTime day)
{
switch (day.DayOfWeek)
{
case DayOfWeek.Monday: return day.AddDays(-1);
case DayOfWeek.Tuesday: return day.AddDays(-2);
case DayOfWeek.Wednesday: return day.AddDays(-3);
case DayOfWeek.Thursday: return day.AddDays(-4);
case DayOfWeek.Friday: return day.AddDays(-5);
case DayOfWeek.Saturday: return day.AddDays(-6);
case DayOfWeek.Sunday: return day.AddDays(-7);
}
return day;
}

public static List<Appointment> SplitAppointment(Appointment appt)
{
TimeSpan oneDay = TimeSpan.FromDays(1);
TimeSpan endOfDay = oneDay; // last possible time of a day
List<Appointment> result = new List<Appointment>();
DateTime currentDay = appt.StartDate;
DateTime endOfCurrentDay = currentDay.Date + endOfDay;
while (endOfCurrentDay < appt.EndDate)
{
result.Add(new Appointment() { StartDate = currentDay, EndDate = endOfCurrentDay });
// copy other attributes of appt
currentDay = currentDay.Date + oneDay; // EDIT: changed this line
endOfCurrentDay += oneDay;
}
if (currentDay < appt.EndDate)
{
result.Add(new Appointment() { StartDate = currentDay, EndDate = appt.EndDate });
// copy other attributes of appt
}
return result;
}

/// <summary>
/// 计算某日起始日期（礼拜一的日期）
/// </summary>
/// <param name="someDate">该周中任意一天</param>
/// <returns>返回礼拜一日期，后面的具体时、分、秒和传入值相等</returns>
public static DateTime GetMondayDate(this DateTime someDate)
{
int i = someDate.DayOfWeek - DayOfWeek.Monday;
if (i == -1) i = 6;// i值 > = 0 ，因为枚举原因，Sunday排在最前，此时Sunday-Monday=-1，必须+7=6。
TimeSpan ts = new TimeSpan(i, 0, 0, 0);
return someDate.Subtract(ts);
}

/// <summary>
/// UTC时间戳起点
/// </summary>
public static readonly DateTime UTCZero = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

/// <summary>
/// 时间转换为时间戳,秒
/// </summary>
/// <param name="time"></param>
/// <returns></returns>
public static long ToTimestamp(this DateTime time)
{
return (long)(time.ToUniversalTime() - UTCZero).TotalSeconds;
}
/// <summary>
/// 时间转换为时间戳，毫秒
/// </summary>
/// <param name="time"></param>
/// <returns></returns>
public static long ToTimestampMilliseconds(this DateTime time)
{
return (time.ToUniversalTime() - UTCZero).Milliseconds;
}
/// <summary>
/// 时间戳转换为UTC时间
/// </summary>
/// <param name="timestamp"></param>
/// <returns></returns>
public static DateTime ToUTCTime(this long timestamp)
{
return UTCZero.AddSeconds(timestamp);
}

/// <summary>
/// 时间戳转换为本地时间
/// </summary>
/// <param name="timestamp"></param>
/// <returns></returns>
public static DateTime ToLocalTime(this long timestamp)
{
return ToUTCTime(timestamp).ToLocalTime();
}

static readonly DateTime unix_time_zero = new DateTime(1970, 1, 1);

public static TimeSpan GetUnixTimeSpan(DateTime utcTime)
{
return utcTime - unix_time_zero;
}

public static TimeSpan GetUnixTimeSpanFromNow()
{
return GetUnixTimeSpan(DateTime.UtcNow);
}

public static DateTime UnixTimeStampToDateTime(this long unixTimeStamp)
{
// Unix timestamp is seconds past epoch
var dtDateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
try
{
dtDateTime = dtDateTime.AddSeconds(unixTimeStamp).ToLocalTime();
}
catch { }
return dtDateTime;
}

public static DateTime MillisecondsToDateTime(this long milliseconds)
{
// Unix timestamp is seconds past epoch
var dtDateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
try
{
dtDateTime = dtDateTime.AddMilliseconds(milliseconds).ToLocalTime();
}
catch { }
return dtDateTime;
}

/// <summary>
/// 距离1970/1/1的秒数，UTC时间
/// </summary>
/// <param name="utcTime"></param>
/// <returns></returns>
public static long GetUnixTimeStamp(this DateTime utcTime)
{
return (long)GetUnixTimeSpan(utcTime).TotalSeconds;
}

/// <summary>
/// 获取本地时间utc时间戳
/// </summary>
/// <param name="localTime"></param>
/// <returns></returns>
public static long GetLocalTimeUnixTimeStamp(this DateTime localTime)
{
return (long)GetUnixTimeSpan(localTime.ToUniversalTime()).TotalSeconds;
}

/// <summary>
/// 距离1970/1/1的毫秒数，UTC时间
/// </summary>
/// <param name="utcTime"></param>
/// <returns></returns>
public static long GetUnixTimeMillisecondsStamp(this DateTime utcTime)
{
return (long)GetUnixTimeSpan(utcTime).TotalMilliseconds;
}

/// <summary>
/// 当前距离1970/1/1的秒数，UTC时间
/// </summary>
public static long GetUnixTimeStampFromNow()
{
return (long)GetUnixTimeSpanFromNow().TotalSeconds;
}

static DateTime year2013 = new DateTime(2013, 1, 1);
public static long GetTicketsFrom2013(this DateTime time)
{
return (time - year2013).Ticks;
}

public static double GetTotalMinutesFrom2013(this DateTime time)
{
return Math.Floor((time - year2013).TotalMinutes);
}

public static DateTime GetDateTimeFrom2013TotalMinutes(this double totalMinutes)
{
return year2013.AddMinutes(totalMinutes);
}

/// <summary>
/// 获得该时间从2013-1-1开始算起的秒数，如果是2013前的时间，返回0
/// </summary>
/// <param name="time"></param>
/// <returns></returns>
public static uint GetSecondsFrom2013(this DateTime time)
{
var span = (time - year2013).TotalSeconds;
if (span > 0)
{
return (uint)span;
}
return 0;
}

/// <summary>
/// 格式化显示时间为几个月,几天前,几小时前,几分钟前,或几秒前
/// 页面使用
/// </summary>
public static string DateStringFromNow(DateTime dt)
{
TimeSpan span = DateTime.Now - dt;
if (span.TotalDays > 365)
{
return dt.ToShortDateString();
}
else if (span.TotalDays > 30)
{
return String.Format("{0}个月前", (int)Math.Floor(span.TotalDays / 30));
}
else if (span.TotalDays > 14)
{
return "2周前";
}
else if (span.TotalDays > 7)
{
return "1周前";
}
else if (span.TotalDays > 1)
{
return String.Format("{0}天前", (int)Math.Floor(span.TotalDays));
}
else if (span.TotalHours > 1)
{
return String.Format("{0}小时前", (int)Math.Floor(span.TotalHours));
}
else if (span.TotalMinutes > 1)
{
return String.Format("{0}分钟前", (int)Math.Floor(span.TotalMinutes));
}
else if (span.TotalSeconds >= 1)
{
return String.Format("{0}秒前", (int)Math.Floor(span.TotalSeconds));
}
else
{
return "1秒前";
}
}

public static int GetIso8601WeekOfYear(this DateTime time)
{
// Seriously cheat. If its Monday, Tuesday or Wednesday, then it'll
// be the same week# as whatever Thursday, Friday or Saturday are,
// and we always get those right
DayOfWeek day = CultureInfo.InvariantCulture.Calendar.GetDayOfWeek(time);
if (day >= DayOfWeek.Monday && day <= DayOfWeek.Wednesday)
{
time = time.AddDays(3);
}
// Return the week of our adjusted day
return CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(time, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);
}

public static DateTime GetCurrentMonth(this DateTime day)
{
return new DateTime(day.Year, day.Month, 1);
}

public static bool IsMonthLastDay(this DateTime day)
{
return day.Date == new DateTime(day.Year, day.Month, 1).AddMonths(1).AddDays(-1);
}

public static DateTime StampToDateTime(string timeStamp)
{
DateTime dateTimeStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
long lTime = long.Parse(timeStamp + "0000");
TimeSpan toNow = new TimeSpan(lTime);
return dateTimeStart.Add(toNow);
}
public static string RsetDateTimeStr(string dateTime)
{
const string defalut1 = "1901/1/1 0:00:00";
const string defalut2 = "0001/1/1 0:00:00";
if (dateTime == defalut1 || dateTime == defalut2)
{
return string.Empty;
}
else
{
return dateTime;
}

}

// <summary>
/// 计算本周起始日期（礼拜一的日期）
/// </summary>
/// <param name="someDate">该周中任意一天</param>
/// <returns>返回礼拜一日期，后面的具体时、分、秒和传入值相等</returns>
public static DateTime CalculateFirstDateOfWeek(DateTime someDate)
{
int i = someDate.DayOfWeek - DayOfWeek.Monday;
if (i == -1) i = 6;// i值 > = 0 ，因为枚举原因，Sunday排在最前，此时Sunday-Monday=-1，必须+7=6。
TimeSpan ts = new TimeSpan(i, 0, 0, 0);
return someDate.Subtract(ts);
}

/// <summary>
/// 计算本周结束日期（礼拜日的日期）
/// </summary>
/// <param name="someDate">该周中任意一天</param>
/// <returns>返回礼拜日日期，后面的具体时、分、秒和传入值相等</returns>
public static DateTime CalculateLastDateOfWeek(DateTime someDate)
{
int i = someDate.DayOfWeek - DayOfWeek.Sunday;
if (i != 0) i = 7 - i;// 因为枚举原因，Sunday排在最前，相减间隔要被7减。
TimeSpan ts = new TimeSpan(i, 0, 0, 0);
return someDate.Add(ts);
}

/// <summary>
/// 判断选择的日期是否是本周（根据系统当前时间决定的‘本周'比较而言）
/// </summary>
/// <param name="someDate"></param>
/// <returns></returns>
public static bool IsThisWeek(DateTime someDate)
{
//得到someDate对应的周一
DateTime someMon = CalculateFirstDateOfWeek(someDate);
//得到本周一
DateTime nowMon = CalculateFirstDateOfWeek(DateTime.Now);
TimeSpan ts = someMon - nowMon;
if (ts.Days < 0)
ts = -ts;//取正
if (ts.Days >= 7)
{
return false;
}
else
{
return true;
}
}

/// <summary>
///获取当前日期在一周里的第几天，sunday默认为0，转换为7
/// </summary>
/// <param name="now"></param>
/// <returns></returns>
public static string GetDayOfWeek(this DateTime now)
{
return now.DayOfWeek == DayOfWeek.Sunday ? "7" : now.DayOfWeek.ToString("D");
}

/// <summary>
/// 时间拼接时分秒 时间2017-06-27 00:00:00 转换后变成2017-06-27 23：59：59
/// </summary>
/// <param name="now"></param>
/// <returns></returns>
public static DateTime AppendDateHMS(this DateTime now)
{
return now.AddHours(23).AddMinutes(59).AddSeconds(59);
}

/// <summary>
/// 获取当前时间，精确到小时
/// </summary>
/// <returns></returns>
public static DateTime GetCurrentHourTime()
{
var now = DateTime.Now;
var time = new DateTime(now.Year, now.Month, now.Day, now.Hour, 0, 0);
return time;
}

public static string GetTimeStamp(this DateTime dateTime)
{
return ((Int32)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds).ToString();
}

private static DateTime MySqlNullDatetime = new DateTime(1, 1, 1, 0, 0, 0);
public static bool IsMySqlDateTimeNull(this DateTime @this)
{
return MySqlNullDatetime == @this;
}