C# 有没有更好的方法将 DateTime 修剪到特定精度？

Is there a better way to trim a DateTime to a specific precision?

提问by Lloyd Cotten

What's the best way to trim a DateTime object to a specific precision? For instance, if I have a DateTime with a value of '2008-09-29 09:41:43', but I only want it's precision to be to the minute, is there any better way to do it than this?

将 DateTime 对象修剪到特定精度的最佳方法是什么？例如，如果我有一个值为“2008-09-29 09:41:43”的 DateTime，但我只希望它的精度达到分钟，有没有比这更好的方法呢？

private static DateTime TrimDateToMinute(DateTime date)
{
    return new DateTime(
        date.Year, 
        date.Month, 
        date.Day, 
        date.Hour, 
        date.Minute, 
        0);
}

What I would really want is to make it variable so that I could set its precision to the second, minute, hour, or day.

我真正想要的是使其可变，以便我可以将其精度设置为秒、分、小时或天。

采纳答案by Bartek Szabat

static class Program
{
    //using extension method:
    static DateTime Trim(this DateTime date, long roundTicks)
    {
        return new DateTime(date.Ticks - date.Ticks % roundTicks, date.Kind);
    }

    //sample usage:
    static void Main(string[] args)
    {
        Console.WriteLine(DateTime.Now);
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerDay));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerHour));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerMillisecond));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerMinute));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerSecond));
        Console.ReadLine();
    }

}

回答by Rikalous

You could use an enumeration

您可以使用枚举

public enum DateTimePrecision
{
  Hour, Minute, Second
}

public static DateTime TrimDate(DateTime date, DateTimePrecision precision)
{
  switch (precision)
  {
    case DateTimePrecision.Hour:
      return new DateTime(date.Year, date.Month, date.Day, date.Hour, 0, 0);
    case DateTimePrecision.Minute:
      return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, 0);
    case DateTimePrecision.Second:
      return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second);
    default:
      break;
  }
}

and expand as required.

并根据需要进行扩展。

回答by Bartek Szabat

    static DateTime TrimDate(DateTime date, long roundTicks)
    {
        return new DateTime(date.Ticks - date.Ticks % roundTicks);
    }

    //sample usage:
    static void Main(string[] args)
    {
        Console.WriteLine(DateTime.Now);
        Console.WriteLine(TrimDate(DateTime.Now, TimeSpan.TicksPerDay));
        Console.WriteLine(TrimDate(DateTime.Now, TimeSpan.TicksPerHour));
        Console.WriteLine(TrimDate(DateTime.Now, TimeSpan.TicksPerMillisecond));
        Console.WriteLine(TrimDate(DateTime.Now, TimeSpan.TicksPerMinute));
        Console.WriteLine(TrimDate(DateTime.Now, TimeSpan.TicksPerSecond));
        Console.ReadLine();
    }

回答by Gunarathinam

DateTime dt = new DateTime()
dt = dt.AddSeconds(-dt.Second)

Above code will trim seconds.

上面的代码将修剪秒。

回答by rocketsarefast

I like this method. Someone mentioned it was good to preserve the Date Kind, etc. This accomplishes that because you dont have to make a new DateTime. The DateTime is properly cloned from the original DateTime and it simply subtracts the remainder ticks.

我喜欢这个方法。有人提到保留 Date Kind 等很好。这样做是因为您不必创建新的 DateTime。DateTime 是从原始 DateTime 正确克隆的，它只是减去剩余的刻度。

public static DateTime FloorTime(DateTime dt, TimeSpan interval) 
{
  return dt.AddTicks(-1 * (dt.Ticks % interval.Ticks));
}

usage:

用法：

dt = FloorTime(dt, TimeSpan.FromMinutes(5)); // floor to the nearest 5min interval
dt = FloorTime(dt, TimeSpan.FromSeconds(1)); // floor to the nearest second
dt = FloorTime(dt, TimeSpan.FromDays(1));    // floor to the nearest day

回答by Marcos Arruda

There are some good solutions presented here, but when I need to do this, I simply do:

这里提供了一些很好的解决方案，但是当我需要这样做时，我只是这样做：

DateTime truncDate;
truncDate = date.Date; // trim to day
truncDate = date.Date + TimeSpan.Parse(string.Format("{0:HH:00:00}", date)); // trim to hour
truncDate = date.Date + TimeSpan.Parse(string.Format("{0:HH:mm}", date)); // trim to minute
truncDate = date.Date + TimeSpan.Parse(string.Format("{0:HH:mm:ss}", date)); // trim to second

Hope it helps.

希望能帮助到你。