How to avoid freezing in VirtualizingStackPanel.MeasureOverride in grouping virtualized ListView?

Question

When ListView is grouped and

                      ScrollViewer.CanContentScroll="True"
                      ScrollViewer.VerticalScrollBarVisibility="Visible"
                      VirtualizingPanel.IsVirtualizing="True"
                      VirtualizingPanel.IsVirtualizingWhenGrouping="True"
                      VirtualizingPanel.VirtualizationMode="Recycling">

(only IsVirtualizingWhenGrouping="True" above causes freezing)

scrolling down causes entire program to freeze. It never becomes active again. When breaking in VS2015 the callstack looks like this:

PresentationFramework.dll!System.Windows.Controls.VirtualizingStackPanel.MeasureOverrideImpl(System.Windows.Size constraint, ref double? lastPageSafeOffset, ref System.Collections.Generic.List<double> previouslyMeasuredOffsets, ref double? lastPagePixelSize, bool remeasure) + 0x3408 bytes   
PresentationFramework.dll!System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(System.Windows.Size constraint) + 0xda bytes   
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!MS.Internal.Helper.MeasureElementWithSingleChild(System.Windows.UIElement element, System.Windows.Size constraint) + 0x48 bytes   
PresentationFramework.dll!System.Windows.Controls.ItemsPresenter.MeasureOverride(System.Windows.Size constraint) + 0x13 bytes   
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!MS.Internal.Helper.MeasureElementWithSingleChild(System.Windows.UIElement element, System.Windows.Size constraint) + 0x48 bytes   
PresentationFramework.dll!System.Windows.Controls.ContentPresenter.MeasureOverride(System.Windows.Size constraint) + 0x13 bytes 
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!System.Windows.Controls.Border.MeasureOverride(System.Windows.Size constraint) + 0x2d2 bytes  
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!System.Windows.Controls.DockPanel.MeasureOverride(System.Windows.Size constraint) + 0x102 bytes   
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!System.Windows.Controls.Control.MeasureOverride(System.Windows.Size constraint) + 0x5e bytes  
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!System.Windows.Controls.Control.MeasureOverride(System.Windows.Size constraint) + 0x5e bytes  
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationFramework.dll!System.Windows.Controls.VirtualizingStackPanel.MeasureChild(ref System.Windows.Controls.Primitives.IItemContainerGenerator generator, ref System.Windows.Controls.Primitives.IContainItemStorage itemStorageProvider, ref System.Windows.Controls.Primitives.IContainItemStorage parentItemStorageProvider, ref object parentItem, ref bool hasUniformOrAverageContainerSizeBeenSet, ref double computedUniformOrAverageContainerSize, ref double computedUniformOrAverageContainerPixelSize, ref bool computedAreContainersUniformlySized, ref System.Collections.IList items, ref object item, ref System.Collections.IList children, ref int childIndex, ref bool visualOrderChanged, ref bool isHorizontal, ref System.Windows.Size childConstraint, ref System.Windows.Rect viewport, ref System.Windows.Controls.VirtualizationCacheLength cacheSize, ref System.Windows.Controls.VirtualizationCacheLengthUnit cacheUnit, ref bool foundFirstItemInViewport, ref double firstItemInViewportOffset, ref System.Windows.Size stackPixelSize, ref System.Windows.Size stackPixelSizeInViewport, ref System.Windows.Size stackPixelSizeInCacheBeforeViewport, ref System.Windows.Size stackPixelSizeInCacheAfterViewport, ref System.Windows.Size stackLogicalSize, ref System.Windows.Size stackLogicalSizeInViewport, ref System.Windows.Size stackLogicalSizeInCacheBeforeViewport, ref System.Windows.Size stackLogicalSizeInCacheAfterViewport, ref bool mustDisableVirtualization, bool isBeforeFirstItem, bool isAfterFirstItem, bool isAfterLastItem, bool skipActualMeasure, bool skipGeneration, ref bool hasBringIntoViewContainerBeenMeasured, ref bool hasVirtualizingChildren) + 0x408 bytes 
PresentationFramework.dll!System.Windows.Controls.VirtualizingStackPanel.MeasureOverrideImpl(System.Windows.Size constraint, ref double? lastPageSafeOffset, ref System.Collections.Generic.List<double> previouslyMeasuredOffsets, ref double? lastPagePixelSize, bool remeasure) + 0x184d bytes   
PresentationFramework.dll!System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(System.Windows.Size constraint) + 0xda bytes   
PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize) + 0x533 bytes  
PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize) + 0x25d bytes  
PresentationCore.dll!System.Windows.ContextLayoutManager.UpdateLayout() + 0x208 bytes   
PresentationCore.dll!System.Windows.ContextLayoutManager.UpdateLayoutCallback(object arg) + 0x22 bytes  
PresentationCore.dll!System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks() + 0x91 bytes   
PresentationCore.dll!System.Windows.Media.MediaContext.RenderMessageHandlerCore(object resizedCompositionTarget) + 0x95 bytes   
PresentationCore.dll!System.Windows.Media.MediaContext.RenderMessageHandler(object resizedCompositionTarget) + 0x71 bytes   
WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate callback, object args, int numArgs) + 0x69 bytes 
WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(object source, System.Delegate callback, object args, int numArgs, System.Delegate catchHandler) + 0x35 bytes    
WindowsBase.dll!System.Windows.Threading.DispatcherOperation.InvokeImpl() + 0x101 bytes 
WindowsBase.dll!MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(object obj) + 0x47 bytes  
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x160 bytes 
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x14 bytes  
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x52 bytes    
WindowsBase.dll!MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0xc8 bytes 
WindowsBase.dll!System.Windows.Threading.DispatcherOperation.Invoke() + 0x60 bytes  
WindowsBase.dll!System.Windows.Threading.Dispatcher.ProcessQueue() + 0x1f4 bytes    
WindowsBase.dll!System.Windows.Threading.Dispatcher.WndProcHook(System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam, ref bool handled) + 0x6d bytes 
WindowsBase.dll!MS.Win32.HwndWrapper.WndProc(System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam, ref bool handled) + 0xbf bytes    
WindowsBase.dll!MS.Win32.HwndSubclass.DispatcherCallbackOperation(object o) + 0x80 bytes    
WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate callback, object args, int numArgs) + 0x69 bytes 
WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.TryCatchWhen(object source, System.Delegate callback, object args, int numArgs, System.Delegate catchHandler) + 0x35 bytes    
WindowsBase.dll!System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority priority, System.TimeSpan timeout, System.Delegate method, object args, int numArgs) + 0x164 bytes 
WindowsBase.dll!MS.Win32.HwndSubclass.SubclassWndProc(System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam) + 0x14b bytes

So my question is: How to avoid freezing and still have grouping virtualization?

char m · Answer 1 · 2018-03-22T09:36:00.733

4

If I specify

VirtualizingPanel.ScrollUnit="Item"

it does not freeze while scrolling.

This is rather strange because:

Property Value Type: System.Windows.Controls.ScrollUnit

A value that indicates whether scrolling is measured as items in the collection or as pixels. The default is Item.

For me all this appears as yet another bug in WPF.

edited Mar 22 '18 at 09:36

answered Mar 21 '18 at 15:03

char m

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How to avoid freezing in VirtualizingStackPanel.MeasureOverride in grouping virtualized ListView?

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