What's the easiest and most robust way of altering the .NET DateTimePicker control, to allow users to enter null
values?
You don't need to modify it to do this.
The DateTimePicker
in .net actually has a checkbox built-in.
Set the ShowCheckBox
property to true
.
Then you can use the Checked
property to see if the user has entered a value.
http://msdn.microsoft.com/en-us/library/system.windows.forms.datetimepicker.showcheckbox(VS.80).aspx