我在C#中使用DateTime
来显示时间。在构建时间时,每个人都使用什么日期部分?
例如,以下内容无效,因为没有第0个月或第0天:
// 4:37:58 PM
DateTime time = new DateTime(0, 0, 0, 16, 47, 58);
我是否使用COM的零日期?
// 4:37:58 PM
DateTime time = new DateTime(1899, 12, 30, 16, 47, 58);
或者是SQL Server的?
//4:37:58 PM
DateTime time = new DateTime(1900, 1, 1, 16, 47, 58);
我意识到这是任意的,因为我将忽略代码中的日期部分,但它仍然可以使用:
DateTime duration = time2 - time1;
回答
我想我喜欢MinValue
DateTime time = DateTime.MinValue.Date.Add(new TimeSpan(16, 47, 58));
注意:我不能使用TimeSpan
,因为它不存储一天中的时间。我之所以知道这一点,是因为没有办法将其内容显示为一段时间。
也就是说,TimeSpan
记录的是一段时间,而不是一天中的某个时间,例如:
TimeSpan t = new TimeSpan(16, 47, 58);
t.ToString();
返回一段时间,格式为hoursminutesseconds,例如:
16:47:58
而不是一个时间:
4:47:58 PM (United States)
04:47:58 nm (South Africa)
4:47:58.MD (Albania)
16:47:58 (Algeria)
04:47:58 م (Bahrain)
PM 4:47:58 (Singapore)
下午 04:47:58 (Taiwan)
04:47:58 PM (Belize)
4:47:58 p.m. (New Zealand)
4:47:58 μμ (Greece)
16.47.58 (Italy)
오후 4:47:58 (Korea)
04:47:58 ب.ظ (Iran)
ਸ਼ਾਮ 04:47:58 (India)
04:47:58 p.m. (Argentina)
etc
换句话说,timespan和time是有区别的。还要认识到,TimeSpan
没有提供将一段时间转换为一天中的某个时间的机制--这是有原因的。
发布于 2008-12-16 20:40:36
那DateTime.MinValue呢?
发布于 2009-05-18 23:07:49
让我们来帮助那些想要时间结构的人:
/// <summary>
/// Time structure
/// </summary>
public struct Time : IComparable
{
private int minuteOfDay;
public static Time Midnight = "0:00";
private static int MIN_OF_DAY = 60 * 24;
public Time(int minuteOfDay)
{
if (minuteOfDay >= (60 * 24) || minuteOfDay < 0)
throw new ArgumentException("Must be in the range 0-1439", "minuteOfDay");
this.minuteOfDay = minuteOfDay;
}
public Time(int hour, int minutes)
{
if (hour < 0 || hour > 23)
throw new ArgumentException("Must be in the range 0-23", "hour");
if (minutes < 0 || minutes > 59)
throw new ArgumentException("Must be in the range 0-59", "minutes");
minuteOfDay = (hour * 60) + minutes;
}
#region Operators
public static implicit operator Time(string s)
{
var parts = s.Split(':');
if (parts.Length != 2)
throw new ArgumentException("Time must be specified on the form tt:mm");
return new Time(int.Parse(parts[0]), int.Parse(parts[1]));
}
public static bool operator >(Time t1, Time t2)
{
return t1.MinuteOfDay > t2.MinuteOfDay;
}
public static bool operator <(Time t1, Time t2)
{
return t1.MinuteOfDay < t2.MinuteOfDay;
}
public static bool operator >=(Time t1, Time t2)
{
return t1.MinuteOfDay >= t2.MinuteOfDay;
}
public static bool operator <=(Time t1, Time t2)
{
return t1.MinuteOfDay <= t2.MinuteOfDay;
}
public static bool operator ==(Time t1, Time t2)
{
return t1.GetHashCode() == t2.GetHashCode();
}
public static bool operator !=(Time t1, Time t2)
{
return t1.GetHashCode() != t2.GetHashCode();
}
/// Time
/// Minutes that remain to
/// Time conferred minutes
public static Time operator +(Time t, int min)
{
if (t.minuteOfDay + min < (24 * 60))
{
t.minuteOfDay += min;
return t;
}
else
{
t.minuteOfDay = (t.minuteOfDay + min) % MIN_OF_DAY;
return t;
}
}
public static Time operator -(Time t, int min)
{
if (t.minuteOfDay - min > -1)
{
t.minuteOfDay -= min;
return t;
}
else
{
t.minuteOfDay = MIN_OF_DAY + (t.minuteOfDay - min);
return t;
}
}
public static TimeSpan operator -(Time t1, Time t2)
{
return TimeSpan.FromMinutes(Time.Span(t2, t1));
}
#endregion
public int Hour
{
get
{
return (int)(minuteOfDay / 60);
}
}
public int Minutes
{
get
{
return minuteOfDay % 60;
}
}
public int MinuteOfDay
{
get { return minuteOfDay; }
}
public Time AddHours(int hours)
{
return this + (hours * 60);
}
public int CompareTo(Time other)
{
return this.minuteOfDay.CompareTo(other.minuteOfDay);
}
#region Overrides
public override int GetHashCode()
{
return minuteOfDay.GetHashCode();
}
public override string ToString()
{
return string.Format("{0}:{1:00}", Hour, Minutes);
}
#endregion
///
/// Safe enumerering - whatever interval applied max days
///
/// Start time
/// Spring in minutes
///
public static IEnumerable Range(Time start, int step)
{
return Range(start, start, step);
}
///
/// Safe enumeration - whatever interval applied max days
///
public static IEnumerable Range(Time start, Time stop, int step)
{
int offset = start.MinuteOfDay;
for (var i = 0; i < Time.Span(start, stop); i += step)
{
yield return Time.Midnight + (i + offset);
}
}
///
/// Calculates the number of minutes between t1 and t2
///
public static int Span(Time t1, Time t2)
{
if (t1 < t2) // same day
return t2.MinuteOfDay - t1.MinuteOfDay;
else // over midnight
return MIN_OF_DAY - t1.MinuteOfDay + t2.MinuteOfDay;
}
}
发布于 2008-12-16 20:41:08
TimeSpan当然可以存储一天中的时间-您只需将该值视为自午夜以来经过的时间量,基本上与我们读取时钟的方式相同。
https://stackoverflow.com/questions/372601
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