DateTime "null" value
I've been searching a lot but couldn't find a solution. How do you deal with a DateTime that should be able to contain an uninitialized value (equivalent to null)? I have a class which might have a DateTime property value set or not. I was thinking of initializing the property holder to DateTime.MinValue, which then could easily be checked. I guess this is a quite common question, how do you do that?
For normal DateTimes, if you don't initialize them at all then they will match DateTime.MinValue , because it is a value type rather than a reference type.
You can also use a nullable DateTime, like this:
DateTime? MyNullableDate;
Or the longer form:
Nullable<DateTime> MyNullableDate;
And, finally, there's a built in way to reference the default of any type. This returns null for reference types, but for our DateTime example it will return the same as DateTime.MinValue :
default(DateTime)
If you're using .NET 2.0 (or later) you can use the nullable type:
DateTime? dt = null;
or
Nullable<DateTime> dt = null;
then later:
dt = new DateTime();
And you can check the value with:
if (dt.HasValue)
{
// Do something with dt.Value
}
Or you can use it like:
DateTime dt2 = dt ?? DateTime.MinValue;
You can read more here:
http://msdn.microsoft.com/en-us/library/b3h38hb0.aspx
DateTime? MyDateTime{get;set;}
MyDateTime = (drOrder["Field1"] == DBNull.Value) ? (DateTime?)null : ((DateTime)drOrder["Field1"]);
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