Date picker doesnt allow edit and no null accepting

I am new to .NET 3.5 , WPF, infragistics and MVVM.

I have two calender control开发者_如何学Pythons and button control ( when clicking the button user see a list of events between the date range. We follow MVVM pattern

1. Start Date(Date Picker) 2. End date(Date Picker) 3. search button

My bussiness gave me some set of rules through which user will be validated.

I have done all validation for the date controls except for the following two:

1. when editing the date picker (manually with out using calender and typing the date) the change event is never recognized in View Model

2. Date picker is not allowing null values ( i need my one my date picker to be empty in page load).

If any body wants i can post my code also..

thanks Divya

There is an ASP.NET version of the datepicker that allows nullable, found here on CodeProject. There was a similar question posted but it was for WinForms here. Ok, the code is for Winforms, maybe you might be able to port it for webforms i.e. asp.net.

Hope this helps, Best regards, Tom.