如何在C＃中解析可为空的DateTime对象

Question

command.Parameters.Add("@EndDate", SqlDbType.DateTime).Value = 
     EndDate == null ? 
        (DateTime?)null : 
        DateTime.Parse(EndDate.ToShortDateString() + " " + EndTime);

EndDate is of type DateTime? and EndTime is just a string containing time. But it is giving me error while parsing because EndDate is a nullable DateTime. How can I parse this ?

Answer 1

由于EndDate是可为空的，因此您可以像这样解析它。

DateTime.Parse(EndDate.Value.ToShortDateString() + " " + EndTime);

Answer 2

尝试使用下面的方法获取值

DateTime.Parse(EndDate.GetValueOrDefault().ToShortDateString() + " " + EndTime);

Answer 3

我通常使用default(DateTime?)并且您还需要强制转换为可空的DateTime对象：

return EndDate.HasValue ? DateTime.Parse(EndDate.Value.ToShortDateString() + " " + EndTime) as DateTime? : default(DateTime?)

Answer 4

You need to use: EndDate.HasValue.ToShortDateString():

Converting your code:

command.Parameters.Add("@EndDate", SqlDbType.DateTime).Value = 
EndDate.HasValue == false ? 
(DateTime?)null : 
DateTime.Parse(EndDate.HasValue.ToShortDateString() + " " + EndTime);

You could also write the following:

        var endDateParameter = endDate.HasValue ?
        new SqlParameter("EndDate", DateTime.Parse(EndDate.HasValue.ToShortDateString() + " " + EndTime)) :
        new SqlParameter("EndDate", typeof(System.DateTime));

Cheers, Noah