RadJumpList - null ref except GroupPickerItemTap

[Heather]

Utilizing a RadJumpList sorted alphabetically with a custom group picker item list (as seen in the Telerik help documentation) as well as an event handler for the group picker item tap event (also as seen in the help docs) and receiveing a null ref exception when an item is selected for which there are no groups in the RadJumpList.Groups.

string alphabet = "#abcdefghijklmnopqrstuvwxyz";
List<string> groupPickerItems = new List<string>(32);
foreach (char c in alphabet)
{
    groupPickerItems.Add(new string(c, 1));
}
MainListBox.GroupPickerItemsSource = groupPickerItems;

private void GroupPicker_ItemTap(object sender, GroupPickerItemTapEventArgs e)
{
    foreach (DataGroup group in MainListBox.Groups)
    {
        if (object.Equals(e.DataItem, group.Key))
        {
            e.DataItemToNavigate = group;
            return;
        }
    }
}

[Deyan]

Hi Heather,

Thanks for writing and for reporting this issue.

Could you please prepare a small Windows Phone 7 application that we can use to reproduce the exception. This will help us directly investogate the case and see how we can further assist you.

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

All the best,
Deyan
the Telerik team

[Renfred]

Hi Deyan,

May I ask is this issue fixed? I'm using the latest 1116 version and having exactly the same issue. This issue did not present in version 910 and 1026.

I dig a little deeper into the issue, mine was caused by having non-empty ListHeader or ListFooter (either content or template). If I remove all ListHeaderContent, ListHeaderTemplate, ListFoorterContent and ListFooterTemplate, the problem would go away.

Another issue of this is my GroupHeader is very close to the edge, therefore tapping on the GroupHeader caused the CheckMode to be activated, instead of opening up GroupListPicker, and therefore causing the NullReferenceException. If I tap non that close to the edge, then GroupListPicker open up properly. So it sort of concludes NullReferenceException wasn't caused by the picker but the CheckMode. And the my cause of NullReferenceException in CheckMode has nothing related to GroupDescriptor or TemplateSelector, it was caused by ListHeader and ListFooter having empty dataItem when the JumpList was checking for IsItemInViewPort.

Hope you get what I mean and hope this helps.

[Deyan]

Hi Renfred,

Thanks for writing.

We have actually not been able to reproduce this issue and thus we have not investigated it. If you could provide us with a demo project that also reproduces the other issues you're reporting, we will be able to directly take a look at them and undertake the needed steps to address these issues.

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

We look forward to receiving the requested details.

Thanks for your time.

Kind regards,
Deyan
the Telerik team