Page becomes blank after being minimized for a while

[Jason Xiao]

We have a Telerik Gridview in a silverlight webpage with two storyboard updates: the 1st storyboard moves the selected item down one record at every 15 sec, and the 2nd storyboard refresh the gridview with updated data every 15 mins. We noticed that after the internet brower is minimized or the silverlight page is put on an inactive hidden brower tab for a while, and the brower or tab is actived again, the page will become blank. Here is the error message from the page error window:

Message

 

: Unhandled Error in Silverlight Application

 

Code

: 4004

 

Category

: ManagedRuntimeError

 

Message

 

: System.NullReferenceException: Object reference not set to an instance of an object.

 

at Telerik

.Windows.Controls.GridView.GridViewItemContainerGenerator.Remove(GeneratorPosition position, Int32 count, Boolean isRecycling)

 

at Telerik

.Windows.Controls.GridView.GridViewItemContainerGenerator.System.Windows.Controls.Primitives.IRecyclingItemContainerGenerator.Recycle(GeneratorPosition position, Int32 count)

 

at Telerik

.Windows.Controls.GridView.GridViewVirtualizingPanel.CleanupRange(IList children, IItemContainerGenerator generator, Int32 startIndex, Int32 count)

 

at Telerik

.Windows.Controls.GridView.GridViewVirtualizingPanel.CleanupContainers(Int32 firstViewport, BaseItemsControl itemsControl)

 

at Telerik

.Windows.Controls.GridView.GridViewVirtualizingPanel.MeasureOverride(Size constraint)

 

at System

.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)

We never had this problem when we use MS Silverlight Gridview.

Anyone has any idea what we should do to fix this?

 

Thanks 

[Yavor Georgiev]

Hello Jason Xiao,

 Unfortunately, without looking at your application it's difficult to pinpoint the issue, but from the stacktrace you've provided us, it's evident it has to to with virtualization. Could you please open a support ticket and send us a copy of your application?

All the best,
Yavor Georgiev
the Telerik team