Question

我有一个日期值（例如2011-04-11 07：45：00.000），我从我的数据库中提取（通过实体框架）。我需要从原始日期值（例如07:45:00）拉出小时，获取当前时间，然后从数据库时间值中减去当前时间。在伪代码中，我希望做这样的事情：

Dim my_date as DateTime = from_db ' This is the value pulled from the database.
Dim this_date as DateTime = Date.Now ' This is pulled via a VB.NET function.
Dim my_hour = my_date_but_only_hours ' Somehow, I need to strip the date off the my_date
Dim this_hour = this_date_but_only_hours ' Same as line above.
Dim hour_difference = my_hour - this_hour
Response.Write("There are " & hour_difference & " hours left before the time runs out.")

Answer 1

my_date.Subtract(this_date).TotalHours

或

my_date.TimeOfDay.Subtract(this_date.TimeOfDay).TotalHours

Answer 2

您可以使用DateTime.TimeOfDay丢弃日期组件。然后，您可以计算表示为TimeSpan的差异。这使您可以访问有关小时差异的信息：

Dim dbTimeOfDay = from_db.TimeOfDay
Dim nowTimeOfDay = DateTime.Now.TimeOfDay
Dim timeDifference = dbTimeOfDay - nowTimeOfDay
Dim hoursDifference = timeDifference.TotalHours

变量hoursDifference是Double，其中分数和秒包含在分数中。如果需要，您可以对其进行舍入或截断。

Answer 3

Dim dbDate = from_db.TimeOfDay  'This gets you a TimeSpan object representing just the time of day in that date.

如果您只想要小时，请继续：

dim dbHour = dbDate.Hour

从两个日期值获得小时/分钟的差异

3 个答案: