BringIntoView doesn't work

[Alessandro]

Hi,
it seems that BringIntoView method doesn't work on the new DataBoundListBox, while has always worked on Windows Phone 8.0 in other UI product.
Indeed when invoked, the list content becomes blank and if I scroll then the content reappers, but the scroll of items stutters and  shows always the same items (a few ) to then go up again to the focused item.

On other hand the Listbox control has no problem in ScrollIntoView method.

Regards.

Alessandro Valente

[Beshoy]

I have noticed random stuttering (as you mentioned) in Windows Phone 8.1 in general. The Xbox Music app, my app, all seem to have this issue.

[Alessandro]

[quote]Beshoy said:I have noticed random stuttering (as you mentioned) in Windows Phone 8.1 in general. The Xbox Music app, my app, all seem to have this issue.[/quote]

Hi,
problem is that list becomes blank when BringIntoView is invoked! :(
As for stuttering, it doesn't happen always.
I hope it'll be fixed in next beta release.

[Ivaylo Gergov]

Hi,

Indeed I was able to reproduce this erroneous behavior(stuttering) and we will address it for our official release. However, I cannot get a blank list using the BringIntoView() method. Could you please send me a sample project so that we can further investigate this? 

Thanks for the valuable feedback.

Regards,
Ivaylo Gergov
Telerik

 

 

[Alessandro]

Hi Ivaylo,
thank for your assistance.
The blank list is caused because the itemssource is binded to a viewmodel property (observablecollection). The BringIntoView method is invoked in a button click sub.
This behavior doesn't happen if I build a new simple project where itemssource is simply a List<string> built into OnNavigatedTo event and NOT binded to a viewmodel property. Nevertheless BringIntoView fails to focus the list on a element such as that on position 20. I do this on a button click sub: 

string s = this.list.ItemsSource.OfType<string>().ElementAt(80);
this.list.BringIntoView(s);

[Vladislav]

Hello Alessandro,

Thank you for the additional information provided. I think that I am able to reproduce the described problem. It seems that the "blank list" appears only before any scrolling is made in the RadDataBoundListBox (if I manually scroll to some element, after that the "blank list" do NOT appear). And moreover the requested item is not brought correctly into view (the view is scrolled "near" it, but not exactly to it). This definitely seems like a problem/bug and we will do our best to resolve it for some consecutive release.

I have attached a sample project showing my attempt to reproduce the described issue.
Can you please check it and modify it (if necessary), in order to be sure that we are discussing exactly the same issue?

Thank you in advance.

Regards,
Vladislav
Telerik

 

 

[Alessandro]

Hi Vladislav ,

here it is my experience using your demo project with my Nokia Lumia 930 (best WP so far ;) ).
1) the list is loaded
2) I click the button (so without scrolling the list)
3) the list becomes blank
4) I click the button again and the list loads as usual as in 1) but there is no focus element even though I can scroll the list without problems
5) I click again the button and the list focuses near the element choosed to focus on code
6) I click again the button and this time focuses on the right element .

On the other hand:

1) if I scroll the list before I click the button the list focuses first near the right element and if I click again then focuses on the right element.
2) the *worst side effect* is that the list scrolls repeating the same elements :( :( :(

You can count on me as beta tester, I absolutely love the new windows Phone 8.1 UI and new elements but withouth your RadDataBoundList I think I'll never publish a very good app.

Hope you'll fix these issues soon :)

Best Regards.

Alessandro

 

[Vladislav]

Hi Alessandro,

Thank you very much for your collaboration.
We can confirm that the described problems are caused by a bug in the RadDataBoundListBox control.
It is logged here, where you can check it's progress and vote for it.

We will do our best to fix it for the upcoming official release (mid October).
And as soon it is fixed we will make a custom build for the participants in the "Early adopters" program.

Your Telerik points are updated as a small appreciation for your valuable feedback.

Regards,
Vladislav
Telerik

 

 

[Alessandro]

Hi Vladislav,
thank you for updating my Telerik points!
I'm very glad to collaborate with such a great team which let me develop beautiful and smart apps.

:)