Gets a value indicating whether the SelectedDate is [Null]. There is no DateTime Null value in .NET, so DateTime.MinValue is returned to represent [Null].
Is the SelectedDate DateTime.MinValue (Null).
The DateTime object is a value type and can not be null. BasicDatePicker uses DateTime.MinValue to represent a Null DateTime.
The IsNull property allows for easy checking of empty dates.
if(!BasicDatePicker1.IsNull && BasicDatePicker1.IsDate)
Response.Write("Valid");
else
Response.Write("Invalid");
If you are using a DataReader, using the IsDBNull method simplifies setting the SelectedDate.
BasicDatePicker1.SelectedDate = myReader.IsDBNull(0) ? DateTime.MinValue : myReader.GetDateTime(0) //<--- 0 is the column in the DataReader.
BasicDatePicker Class | BasicFrame.WebControls Namespace | IsDate | DateTime.MinValue