简单的问题。我有一个有序的日期集合。顺便说一下,它们是英国日期
01/01/10
01/02/10
01/03/10
01/04/10
02/04/10
03/04/10
04/04/10
我想将其转换为日期范围的集合
01/01/10 -> 01/01/10
01/02/10 -> 01/02/10
01/03/10 -> 01/03/10
01/04/10 -> 04/04/10
澄清一下,我正在尝试将任何连续日期转换为一个范围。所以前 3 个日期是独立的,后 4 个日期转换为 4 月 1 日到 4 月 4 日的范围。
现在我可以使用循环来做到这一点,但它不是很优雅。有没有人有任何解决方案?
谢谢
请您参考如下方法:
鉴于您想确定连续日期范围的范围,我认为您唯一的选择是,正如您所说的循环。不过,您可以一次性完成,并将其放入扩展方法中,以便它可以在任何 IList<DateTime> 上运行。 ,例如:
// purely an example, chances are this will have actual, y'know logic in live
public class DateRange
{
private List<DateTime> dates = new List<DateTime>();
public void Add(DateTime date)
{
this.dates.Add(date);
}
public IEnumerable<DateTime> Dates
{
get { return this.dates; }
}
}
public static IEnumerable<DateRange> GetRanges(this IList<DateTime> dates)
{
List<DateRange> ranges = new List<DateRange>();
DateRange currentRange = null;
// this presumes a list of dates ordered by day, if not then the list will need sorting first
for( int i = 0; i < dates.Count; ++i )
{
var currentDate = dates[i];
if( i == 0 || dates[i - 1] != currentDate.AddDays(-1))
{
// it's either the first date or the current date isn't consecutive to the previous so a new range is needed
currentRange = new DateRange();
ranges.Add(currentRange);
}
currentRange.Add(currentDate);
}
return ranges;
}
您还可以通过传入 IEnumerable<DateTime> 使其更加通用:
public static IEnumerable<DateRange> GetRanges(this IEnumerable<DateTime> dates)
{
List<DateRange> ranges = new List<DateRange>();
DateRange currentRange = null;
DateTime? previousDate = null;
// this presumes a list of dates ordered by day, if not then the list will need sorting first
foreach( var currentDate in dates )
{
if( previousDate == null || previousDate.Value != currentDate.AddDays(-1) )
{
// it's either the first date or the current date isn't consecutive to the previous so a new range is needed
currentRange = new DateRange();
ranges.Add(currentRange);
}
currentRange.Add(currentDate);
previousDate = currentDate;
}
return ranges;
}
