Issue with missing item when using WrapVirtualizationStrategyDefinition

[An Dinh]

I tried to display list box with simple item as below:

<telerikPrimitives:RadDataBoundListBox Name="listboxProgram"
                 ItemsSource="{Binding VideoPrograms}"
                 EmptyContent=""
                 telerikCore:InteractionEffectManager.IsInteractionEnabled="True"
                 ItemTap="listboxProgram_ItemTap"
                 DataVirtualizationMode="OnDemandAutomatic" >
                 <telerikPrimitives:RadDataBoundListBox.ItemTemplate>
                     <DataTemplate>
                         <Grid Width="200" Height="200" Margin="0,0,10,10">

                             <TextBlock TextWrapping="Wrap" MaxHeight="100"
                                     VerticalAlignment="Bottom"
                                     Text="{Binding Title}"
                                     Foreground="Black"
                                     Margin="5,0,5,5"/>

                         </Grid>
                     </DataTemplate>
                 </telerikPrimitives:RadDataBoundListBox.ItemTemplate>

                 <telerikPrimitives:RadDataBoundListBox.VirtualizationStrategyDefinition>
                     <telerikPrimitives:WrapVirtualizationStrategyDefinition Orientation="Horizontal" />
                 </telerikPrimitives:RadDataBoundListBox.VirtualizationStrategyDefinition>

                 <telerikPrimitives:RadDataBoundListBox.ItemLoadingTemplate>
                     <DataTemplate>
                         <telerikPrimitives:RadBusyIndicator IsRunning="True" Width="410"
                                 Content="" AnimationStyle="AnimationStyle9" />
                     </DataTemplate>
                 </telerikPrimitives:RadDataBoundListBox.ItemLoadingTemplate>

                 <telerikPrimitives:RadDataBoundListBox.ItemAddedAnimation>
                     <telerikCore:RadMoveAnimation StartPoint="500,0" EndPoint="0,0" Duration="0:0:0.8">
                         <telerikCore:RadMoveAnimation.Easing>
                             <ExponentialEase EasingMode="EaseOut"/>
                         </telerikCore:RadMoveAnimation.Easing>
                     </telerikCore:RadMoveAnimation>
                 </telerikPrimitives:RadDataBoundListBox.ItemAddedAnimation>
             </telerikPrimitives:RadDataBoundListBox>

My problem is that: sometimes I scroll down or up on this list. Some items are missing and/or be translated ~200 pixel to the right (item is rendered over the listbox). These issues happen with Telerik Rad Controls Q1 - Q3 2012. Please also take a look at attached image for more details.

I'd like to know if these are already known issues ? Is there any plan to fix it or workaround now ?

[Deyan]

Hi An,

 
Thanks for writing and for the shared details.

We are not aware of similar issues in RadDataBoundListBox when in Wrap Mode. It seems that this issue occurs in the context of your scenario and therefore we will need a sample project which reproduces it to be able to debug it. Can you please prepare such project or directly send us your application for further investigation?

Note that you will have to open a new support ticket in order to be able to attach your project here.

Thanks for your time.

All the best,
Deyan
the Telerik team

[An Dinh]

Hi,

I've already submitted support ticket (ID: 639928) with example project and screenshots of bug.

I also attach bugs screenshots here to see if anyone could face to the same issue.

Thanks,
An Dinh

[Rafał]

I have the exact same problem with very simple layout. Did u managed to fix it?

[Deyan]

Hello Rafal,

Thanks for writing.

Yes, the issue mentioned in this thread has been resolved with a fix from our side. Since this fix has been included in a build from 2012 and you continue experiencing issues, it might be so that they are caused by something different.

Is it possible for you to open a new support ticket and provide us with a sample project that we can use to investigate the issue and see what to do next?

Thanks for your time.

Regards,
Deyan
Telerik

[Shah Z]

hi Deyan.. I understand from this thread that it is already fixed, but i am also experiencing the same issue.. 
From the ticket mention by An Dinh is there a workaround for to fix this issue?

Seriously need help on this..


Shah

[Rosy Topchiyska]

Hello,

Thank you for writing.

We will be very grateful if you send us a sample project that reproduces the issue.

I look forward to your reply.

Regards,
Rosy Topchiyska
Telerik

 

 

[Yauhen]

Hello,

Did you manage to fix the problem? Actually, I have the same one.

I'm using a ListPicker, which is set up to utilize a popup to select a value.
As far as I see, the popup is implemented using DataBoundListBox inside of it. I've just made a little tweak - applied a new style to DataBoundListBox, where I specified utilization of WrapVirtualizationStrategyDefinition.

When the first item from the list is selected, the popup page looks great. As soon as any other item selected, a kind of a line break appears before that item, so no matter how many items are in a WrapRow, the selected item (and the rest of them) starts from a new line.

Please take a look at screencast: http://i.imgur.com/2KEvu58.gif

[Rosy Topchiyska]

Hi Yauhen,

Unfortunately, we could not reproduce this issue on our side. I have attached the sample project that we used to test your scenario. Could you please take a look and modify it to reproduce the problem?

I look forward to your reply. 

Regards,
Rosy Topchiyska
Telerik

 

 

[Yauhen]

Hi Rosy,

Thanks for quick turnaround!

The issue can be reproduced in several ways:

1. The simplest one is just to define SelectedIndex property explicitly:

<telerikInput:RadListPicker ItemsSource="{Binding Items}"
                    Style="{StaticResource RadListPickerStyle1}"
                    SelectedIndex="4">

2. The second one is a bit more real-world example. I've introduced a new landing page, which allows you to navigate to the page with ListPicker. Additionally, I added a kind of a service, which provides ViewModel with immutable data collection and saves the selected value (Color name) like settings in real application do. Please find the sample code (couldn't attach zip): https://www.dropbox.com/s/0awtvj3ya7j347s/WrapStrategy_Bug.zip?dl=0

Looking forward to you answer.
Thanks in advance.

[Rosy Topchiyska]

Hello Yauhen,

Thank you for the information and the example. It helped us to successfully reproduce the problem and our developers will do their best to fix it for the next release of the controls. I have also updated your Telerik points as a token of gratitude for bringing this issue to our attention.

Regards,
Rosy Topchiyska
Telerik