DateTime比较精度

Question

我正在进行DateTime比较,但我不想在秒,毫秒和刻度级别进行比较.什么是最优雅的方式？

如果我只是比较DateTime,那么由于滴答差异,它们很少相等.

Answer 1

那么使用时间跨度呢？

if (Math.Truncate((A - B).TotalMinutes) == 0)
{
    //There is less than one minute between them
}

可能不是最优雅的方式,但它允许相隔一秒但仍然具有不同的日/小时/分钟部分的情况,例如过夜.

编辑:我发现截断是不必要的......

if (Math.Abs((A - B).TotalMinutes) < 1)
{
    //There is less than one minute between them
}

我个人认为这更优雅......

Answer 2

一种方法可能是从您想要比较的值创建两个新的DateTime,但忽略从秒开始的任何内容,然后比较这些:

DateTime compare1 = new DateTime(year1, month1, day1, hour1, minute1, 0);
DateTime compare2 = new DateTime(year2, month2, day2, hour2, minute2, 0);

int result = DateTime.Compare(compare1, compare2);

我是第一个承认它不优雅的人,但它解决了这个问题.

Answer 3

使用TimeSpan,您可以获得所需的所有粒度:

DateTime dt1, dt2;
double d = (dt2 - dt1).TotalDays;
double h = (dt2 - dt1).TotalHours;
double m = (dt2 - dt1).TotalMinutes;
double s = (dt2 - dt1).TotalSeconds;
double ms = (dt2 - dt1).TotalMilliseconds;
double ticks = (dt2 - dt1).Ticks;

Answer 4

public class DateTimeComparer : Comparer<DateTime>
{
    private Prescision _Prescision;

    public enum Prescision : sbyte
    {
        Millisecons,
        Seconds,
        Minutes,
        Hour,
        Day,
        Month,
        Year,
        Ticks
    }

    Func<DateTime, DateTime>[] actions = new Func<DateTime, DateTime>[]
        {
            (x) => { return x.AddMilliseconds(-x.Millisecond);},
            (x) => { return x.AddSeconds(-x.Second);},
            (x) => { return x.AddMinutes(-x.Minute);},
            (x) => { return x.AddHours(-x.Hour);},
            (x) => { return x.AddDays(-x.Day);},
            (x) => { return x.AddMonths(-x.Month);},
        };

    public DateTimeComparer(Prescision prescision = Prescision.Ticks)
    {
        _Prescision = prescision;
    }

    public override int Compare(DateTime x, DateTime y)
    {
        if (_Prescision == Prescision.Ticks)
        {
            return x.CompareTo(y);
        }

        for (sbyte i = (sbyte)(_Prescision - 1); i >= 0; i--)
        {
            x = actions[i](x);
            y = actions[i](y);
        }

        return x.CompareTo(y);
    }
}

用法示例：

new DateTimeComparer(DateTimeComparer.Prescision.Day).Compare(Date1, Date2)