如何检查 DateTime.Now 是否仅在时间部分的两个给定 DateTimes 之间？

Question

对于我的应用，我需要知道 Now() 是否介于两个值之间。

用户可以设置开始和结束时间，这样他就不会被通知打扰（例如在夜间）。

所以如果有两个TimePickers（开始时间和结束时间），用户可以设置。

假设用户将22:00 设置为StartTime，将07:00 设置为EndTime（这将覆盖整个夜晚）。

如何检查DateTime.Now 是否在选定的开始时间和结束时间之间？

编辑： 我只希望它与小时和分钟部分一起使用。因此，如果用户设置了开始和结束时间，这应该适用于每晚。

Answer 1

首先您需要将所有内容转换为相同的单位（我们将使用TimeSpan），然后您需要查看起止时间是否超过午夜，最后根据检查结果进行比较：

// convert everything to TimeSpan
TimeSpan start = new TimeSpan(22, 0, 0);
TimeSpan end = new TimeSpan(07, 0, 0);
TimeSpan now = DateTime.Now.TimeOfDay;
// see if start comes before end
if (start < end)
    return start <= now && now <= end;
// start is after end, so do the inverse comparison
return !(end < now && now < start);

这里有一个函数可以帮你完成：

bool TimeBetween(DateTime datetime, TimeSpan start, TimeSpan end)
{
    // convert datetime to a TimeSpan
    TimeSpan now = datetime.TimeOfDay;
    // see if start comes before end
    if (start < end)
        return start <= now && now <= end;
    // start is after end, so do the inverse comparison
    return !(end < now && now < start);
}

你可以这样称呼它：

bool silenceAlarm = TimeBetween(DateTime.Now, StartTime.Value, EndTime.Value);

Answer 2

由于您只收集两次没有日期，因此您需要确定这两次是否来自同一天。如果将StartTime、EndTime 和Now 放入TimeSpans：

if (StartTime > EndTime) 
{
    // the range crosses midnight, do the comparisons independently
    return (StartTime < Now) || (Now < EndTime);
}
else 
{
    // the range is on the same day, both comparisons must be true
    return StartTime < Now && Now < EndTime;
}

Answer 3

    public static bool isCurrenctDateBetween(DateTime fromDate, DateTime toDate)
    {
        DateTime curent = DateTime.Now.Date;
        if (fromDate.CompareTo(toDate) >= 1)
        {
            MessageBox.Show("From Date shouldn't be grater than To Date", "DateRange",MessageBoxButton.OKCancel, MessageBoxImage.Warning);
        }
        int cd_fd = curent.CompareTo(fromDate);
        int cd_td = curent.CompareTo(toDate);

        if (cd_fd == 0 || cd_td == 0)
        {
            return true;
        }

        if (cd_fd >= 1 && cd_td <= -1)
        {
            return true;
        }
        return false;
    }

Answer 4

DateTime nowDate = DateTime.Now;
// set these to today + time from time picker
DateTime startDate = new DateTime(nowDate.Year, nowDate.Month, nowDate.Day,
    selectedStart.Hour, selectedStart.Minute, 0);
DateTime endDate = new DateTime(nowDate.Year, nowDate.Month, nowDate.Day, 
    selectedEnd.Hour, selectedEnd.Minute, 0);
bool isBetween = nowDate < endDate && nowDate > startDate;

2016 年 6 月 8 日更新
不知道为什么不赞成投票是合适的，因为这是一个可行的解决方案。 OP 确实专门询问了DateTime，但我建议使用TimeSpan，而不是根据@Gabe 的回答。

根据我的回答，这是一个工作功能：

public static bool TimeBetween(DateTime check, DateTime start, DateTime end, bool inclusive = true)
{
    var from = new DateTime(check.Year, check.Month, check.Day, 
        start.Hour, start.Minute, start.Second, start.Millisecond);
    var to = new DateTime(check.Year, check.Month, check.Day, 
        end.Hour, end.Minute, end.Second, end.Millisecond);

    if (inclusive)
        return from <= check && to >= check;

    return from < check && to > check;
}

这是一个有效的小提琴：https://dotnetfiddle.net/vZCXqv。

完整代码：

using System;

public class Program
{
    public static void Main()
    {
        var start = new DateTime(1, 1, 1, 9, 0, 0);
        var end = new DateTime(1, 1, 1, 17, 0, 0);

        Console.WriteLine("{0} - Too early",                TimeBetween(new DateTime(2014, 1, 1, 08, 59, 59, 999), start, end));
        Console.WriteLine("{0} - On start time exclusive",  TimeBetween(new DateTime(2014, 1, 1, 09, 00, 00, 000), start, end, false));
        Console.WriteLine("{0} - On start time inclusive",  TimeBetween(new DateTime(2014, 1, 1, 09, 00, 00, 000), start, end));
        Console.WriteLine("{0} - After start time",         TimeBetween(new DateTime(2014, 1, 1, 09, 00, 00, 001), start, end));        
        Console.WriteLine("{0} - Before end time",          TimeBetween(new DateTime(2014, 1, 1, 16, 59, 59, 999), start, end));
        Console.WriteLine("{0} - On end time inclusive",    TimeBetween(new DateTime(2014, 1, 1, 17, 00, 00, 000), start, end));
        Console.WriteLine("{0} - On end time exclusive",    TimeBetween(new DateTime(2014, 1, 1, 17, 00, 00, 000), start, end, false));
        Console.WriteLine("{0} - Too late",                 TimeBetween(new DateTime(2014, 1, 1, 17, 00, 00, 001), start, end));
    }

    public static bool TimeBetween(DateTime check, DateTime start, DateTime end, bool inclusive = true)
    {
        var from = new DateTime(check.Year, check.Month, check.Day, start.Hour, start.Minute, start.Second, start.Millisecond);
        var to = new DateTime(check.Year, check.Month, check.Day, end.Hour, end.Minute, end.Second, end.Millisecond);

        if (inclusive)
            return from <= check && to >= check;

        return from < check && to > check;
    }
}

Answer 5

直接比较。

如果（日期 > 开始日期 && 日期

Answer 6

Find if current time falls in a time range的骗子

DateTime start = new DateTime(2009, 12, 9, 10, 0, 0));
DateTime end = new DateTime(2009, 12, 10, 12, 0, 0));
DateTime now = DateTime.Now;

if ((now > start) && (now < end))
{
   //match found
}

时间跨度，再次取自欺骗。

TimeSpan start = new TimeSpan(10, 0, 0);
TimeSpan end = new TimeSpan(12, 0, 0);
TimeSpan now = DateTime.Now.TimeOfDay;

if ((now > start) && (now < end))
{
   //match found
}

Answer 7

我用这个，所以你可以直接传递DateTime：

        public static bool TimeBetween(DateTime time, DateTime startDateTime, DateTime endDateTime)
    {
        // get TimeSpan
        TimeSpan start = new TimeSpan(startDateTime.Hour, startDateTime.Minute, 0);
        TimeSpan end = new TimeSpan(endDateTime.Hour, endDateTime.Minute, 0);

        // convert datetime to a TimeSpan
        TimeSpan now = time.TimeOfDay;
        // see if start comes before end
        if (start < end)
            return start <= now && now <= end;
        // start is after end, so do the inverse comparison
        return !(end < now && now < start);
    }