Here are some thoughts on Menu:

- First of all, I haven’t seen people use Menu to display large amounts of information. Is this the right control for what you’re trying to do? What is your scenario? How many items and layers do you have?

- Yeah, I’ve come across the same issue with debugging MenuItems as you mention. I opened the Menu, clicked on Snoop, and the Menu closed. I don’t know of any other tool or way to solve this problem. I’m not sure if there’s anything that WPF can do, since this is the real behavior of Menu. I’ll let Pete (the guy who wrote Snoop) know about this – maybe he can do something in Snoop to improve the experience.

- And last, replying to your question, I think it will be really hard for you to implement the third solution in my series with Menu (the one with full UI virtualization and discarding data on collapse). For TreeView it was quite easy because the layout of a TreeView is very similar to the layout of a ListBox. Menu, however, is very different, so I don’t think it would be possible to leverage the full UI virtualization feature from ListBox. The second solution (the one that discards data on collapse) should be possible, by following similar steps. You may need to copy and change the default template for MenuItem instead of TreeViewItem, and you will have to find different events that will trigger when you attempt to open and close the menu. This will probably not be as straight forward as the TreeView sample, but it should be possible.

Thanks for your comment,
Bea

You have explained very well in your blog about TreeView (It is cool, thank you!). But how about the Menu… do I need to take some actions if I want to display large hierarchical information using Menu? My question probably seems evident for all, but I’m not a WPF expert.

Also, I have found impossible to use Snoop for browsing internals of Menu… First, it seems like menu is not in the visual tree of window. Second, it is hard (or very inconvenient) to do something with Menu, because it is closed each time when i activate another window. Probably you could recommend some technique of using Snoop or some other tool.

Thanks,

Ivan

I’m not sure that I completely understand your scenario. If you start with an empty data entry form, submit the data, and your validation rules fail for null/empty string values, your controls should now be invalid. Validation should fire every time your data is submitted to the source. You can find here a simple project I put together hoping to repro the behavior you describe. I would like to understand your expectations better because we know we have some rough edges in validation, and the more concrete feedback we get about it, the easier it is for us to fix it.

We already have an internal work item tracking adding support for validation on non-bound controls. The priority of that work will grealy depend on how much customers ask for it. I would personally love to see this feature get implemented!

Thanks,
Bea

My question isn’t directly related to the post but instead is a problem with data validation that’s been asked on the MSDN forums but as far as I know not resolved yet.

A good description is at: http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2079199&SiteID=1

The simple case is, I want to start with an empty data-entry form. Some fields are mandatory. If I simply submit my data, the controls will be considered valid, because there has been no update of the underlying data source and hence no validation rules fired.

It would be great to have a good solution to this – and preferably to take this further and be able to do validation on non-bound controls, rather like in ASP.NET.

I hope this feedback is useful to the WPF team!

thanks,

Duncan Millard
http://geekswithblogs.net/dmillard