public static DateInfo OffsetByWeekAfter(DateInfo dt, DayOfWeek dayOfWeek)
{
var daysNeeded = (int)dayOfWeek - (int)dt.DayOfWeek;
return((int)dayOfWeek >= (int)dt.DayOfWeek
? dt.AddDays(daysNeeded)
: dt.AddDays(daysNeeded + 7));
}
public static DateInfo OffsetByWeekBefore(DateInfo dt, DayOfWeek dayOfWeek)
{
var daysSubtract = (int)dayOfWeek - (int)dt.DayOfWeek;
return((int)dayOfWeek < (int)dt.DayOfWeek
? dt.AddDays(daysSubtract)
: dt.AddDays(daysSubtract - 7));
}
/// <summary>
/// Get last day of this week
/// </summary>
/// <param name="d"></param>
/// <param name="cultureInfo"></param>
/// <returns></returns>
public static DateInfo GetLastDayInfoOfWeek(this DateInfo d, CultureInfo cultureInfo)
{
cultureInfo = (cultureInfo ?? CultureInfo.CurrentCulture);
var firstDayOfWeek = cultureInfo.DateTimeFormat.FirstDayOfWeek;
while (d.DayOfWeek != firstDayOfWeek)
{
d = d.AddDays(-1);
}
return(d.AddDays(6));
}
/// <summary>
/// Get previous weekday.
/// </summary>
/// <param name="d"></param>
/// <param name="weekday"></param>
/// <returns></returns>
public static DateInfo GetPreviousWeekdayInfo(this DateInfo d, DayOfWeek weekday)
{
while (d.DayOfWeek != weekday)
{
d = d.AddDays(-1);
}
return(d);
}
/// <summary>
/// Add business days<br />
/// 添加指定个数量的工作日
/// </summary>
/// <param name="d"></param>
/// <param name="days"></param>
/// <returns></returns>
public static DateInfo AddBusinessDays(this DateInfo d, int days)
{
var sign = Math.Sign(days);
var unsignedDays = Math.Abs(days);
for (var i = 0; i < unsignedDays; i++)
{
do
{
d = d.AddDays(sign);
} while (d.DayOfWeek == DayOfWeek.Saturday ||
d.DayOfWeek == DayOfWeek.Sunday);
}
return(d);
}
public static DateInfo AddWeeks(this DateInfo d, int weeks) => d.AddDays(weeks * 7);
/// <summary> /// Get yesterday<br /> /// 前一天 /// </summary> /// <param name="d"></param> /// <returns></returns> public static DateInfo Yesterday(this DateInfo d) => d.AddDays(-1);
/// <summary> /// Add one day<br /> /// 加一天 /// </summary> /// <param name="d"></param> /// <returns></returns> public static DateInfo AddDay(this DateInfo d) => d.AddDays(1);
