如何检查日期在两个给定日期之间

Question

我必须检查我的特定日期是否在两个字符串日期之间或等于它们例如：

var startDay = "Saturday";
var endDay = "Tuesday";
DateTime myDate = DateTime.Now;
if(myDate.DayofWeek >= startDay && myDate.DayofWeek <= endDay){
//some code here...
}

Answer 1

您可以使用 DayOfWeek 枚举。

if(myDate.DayOfWeek >= DayOfWeek.Tuesday 
   && myDate.DayOfWeek <= DayOfWeek.Saturday)
{
    // This would catch the days from Tuesday to Saturday
}

如果你想赶上从星期六到星期二的日子，你必须稍微更改一下你的代码。

    if(myDate.DayOfWeek >= DayOfWeek.Saturday 
    || myDate.DayOfWeek <= DayOfWeek.Tuesday)
{
    // This would catch the days from Tuesday to Saturday
}

如果您的 startDate 和 endDate 正在更改。然后你需要解析第一个并做一些额外的检查。

DayOfWeek startDayOfWeek;
DayOfWeek endDayOfWeek;
if (!Enum.TryParse(startDay, out startDayOfWeek))
{
    // Something wrong happened and you have to handle it.
}
if (!Enum.TryParse(endDay, out endDayOfWeek))
{
    // Something wrong happened and you have to handle it.
}
if (
       ((int)startDayOfWeek < (int)endDayOfWeek
         && myDate.DayOfWeek >= startDayOfWeek
         && myDate.DayOfWeek <= endDayOfWeek)
    || ((int)startDayOfWeek > (int)endDayOfWeek
         && (myDate.DayOfWeek >= startDayOfWeek
             || myDate.DayOfWeek <= endDayOfWeek))
   )
{

}

Answer 2

您可以将这些字符串解析为 DayOfWeek 枚举：

var startDay = "Saturday";
var endDay = "Tuesday";
DayOfWeek startDayOfWeek, endDayOfWeek;
if (!Enum.TryParse(startDay, out startDayOfWeek))
   // error handlnig
if (!Enum.TryParse(endDay, out endDayOfWeek))
   // error handlnig
DateTime myDate = DateTime.Now;
if(myDate.DayofWeek >= startDayOfWeek && myDate.DayofWeek <= endDayOfWeek){
    //some code here...
}

但这会带来另一个问题：DayOfWeek 的值从星期日 (0) 到星期六 (6)。根据您定义的一周开始时间或 between 的含义，您可能需要调整这些值。

所以这里有一个建议：

int startDayAsInt = (int)startDayOfWeek; // the parsed value from above
int endDayAsInt = (int)endDayOfWeek;
int myDateAsInt = (int)myDate.DayOfWeek;

if (endDayAsInt < startDayAsInt) endDayAsInt += 7;
if (myDateAsInt < startDayAsInt) myDateAsInt += 7;
if (myDateAsInt >= startDayAsInt && myDateAsInt <= endDayAsInt)
    // do something

这应该适用于所有组合，因为它会将 "next" 周的天数投射到开始日之前。

如何检查日期在两个给定日期之间

How to check date day is between two given days

c#

datetime

date-comparison