DevForce Community Forum : Nullable DateTimePicker

Nullable DateTimePicker : 1. Bind your datetimepicker.text,...

Mon, 04 Jan 2010 12:39:03 -700

Author: dr_kreso
Subject: 502
Posted: 04-Jan-2010 at 12:39pm

1. Bind your datetimepicker.text, not datetimepicker.value
2. Add this code in datetimepicker_Validating(object sender, CancelEventArgs e) event:

if (!datetimepicker.Checked)
((Order)orderBindingSource.Current).OrderDate= null;

So, you need to manually set your Date to null value

3. ShowCheckBow of datetimepicker must be set to True

I hope it helps!

Nullable DateTimePicker : See the post I last referenced...

Wed, 17 Oct 2007 10:12:07 -700

Author: Customer
Subject: 502
Posted: 17-Oct-2007 at 10:12am

See the post I last referenced (about the custom blue textbox control) to see an example of how to build a custom binder.

Nullable DateTimePicker : Thanks for your quick reply. Yes,...

Wed, 17 Oct 2007 09:05:09 -700

Author: Miszou
Subject: 502
Posted: 17-Oct-2007 at 9:05am

Thanks for your quick reply.

Yes, the reason for using a different nullable date-time picker is due to a customer requirement that no date should be displayed if no date has yet been entered. The .NET date-time picker (is this the same as the DevForce one?) will always display a date, even when the value is null.

It has a strange checkbox implementation that is not intuitive at all - especially as null dates are displayed as todays date, but grayed out.

So, what I would really like, is a datetime picker that allows users to type freehand dates, but also contains a drop down picker. I was hoping to be able to use the control that I mentioned in my initial post, but I don't think it's going to work...

I think I am going to have to write my own control (using http://www.ideablade.com/forum/forum_posts.asp?TID=133 as a reference).

As far as I can see, there are a couple of ways to go about this. I can either create an owner-drawn date-time picker, or I can roll my own, using a combination of a combo-box and a calendar control, which is the direction I am leaning towards at the moment. I can catch the dropdown/up events and display the calendar appropriately and users can also type free text into the combo (which would of course be parsed by a DateConverter).

At some point, I will almost certainly need to host this control in a DataGridView as well, but I am assuming I can follow these instructions to implement that functionality: http://msdn2.microsoft.com/en-us/library/7tas5c80(VS.80).aspx

You also mentioned that you could give me the DataBinder for the NullableDatePicker. If you could provide that, or even just an example of a custom DataBinder, I would be extremely grateful.

Thanks again for your response, and if you think of any additional hints or pitfalls to avoid, please let me know!

Nullable DateTimePicker : I am not entirely sure why you...

Tue, 16 Oct 2007 19:50:22 -700

Author: davidklitzke
Subject: 502
Posted: 16-Oct-2007 at 7:50pm

I am not entirely sure why you don't want to use the DevForce Nullable Date Picker. I assume that you don't like the way it looks when the date is Null.

Here are some options:

(1) You might consider building a custom control based on the Nullable Date Picker. Look at a previous post and the reply at:

http://www.ideablade.com/forum/forum_posts.asp?TID=133

It shows you how to create a custom control (a textbox with a blue background). This custom TextBox will show up in the Designer and will be one of your choices for a TextBox control in your Autopopulate form.

I can give you the DataBinder for the NullableDataPicker.

(2) Use .NET databinding

You can use .NET databinding to bind to DevForce objects

Edited by davidklitzke - 16-Oct-2007 at 7:50pm

Nullable DateTimePicker : I am trying to databinda nullable...

Tue, 16 Oct 2007 11:05:49 -700

Author: Miszou
Subject: 502
Posted: 16-Oct-2007 at 11:05am

I am trying to databind a nullable DateTime to the DateTimePicker in .NET.

However, it does not appear to be working as I would expect - and I'm not sure if this is due to the 3rd party DateTimePicker controls I am using, or whether the DateConverter is somehow translating the data prior to display.

I have tried several free controls that I have found on the internet, but none of them seem to work properly when binding to an EntityList. I am particularly interested in using this one http://www.codeproject.com/cs/miscctrl/NullableDateTimePicker.asp as I like the display when there is no date. (a prompt string instead of an unchecked checkbox and todays date).

I realize that you probably aren't going to support this guys control (!), but I was wondering if you could perhaps point me in the right direction. I am wondering whether I have to create my own DataConverter to support null values? And if so, would you happen to have a DateConverter that supports null values just sort of lying around?

Basically, do I need to write my own DevForce specific DateTimePicker and/or DateConverter to get it to work as I want?

Thanks for your help.