Freeze while selecting item in the results tree

Randomly the UI freezes when selecting an item after doing a search.

When breaking in the code it seems to be stuck while measuring items in the VirtualizingStackPanel:

 	PresentationCore.dll!System.Windows.Media.Visual.GetDpi()	Inconnu
 	PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize)	Inconnu
 	PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize)	Inconnu
 	PresentationFramework.dll!System.Windows.Controls.Grid.MeasureCell(int cell, bool forceInfinityV)	Inconnu
 	PresentationFramework.dll!System.Windows.Controls.Grid.MeasureCellsGroup(int cellsHead, System.Windows.Size referenceSize, bool ignoreDesiredSizeU, bool forceInfinityV, out bool hasDesiredSizeUChanged)	Inconnu
 	PresentationFramework.dll!System.Windows.Controls.Grid.MeasureOverride(System.Windows.Size constraint)	Inconnu
 	PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize)	Inconnu
 	PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize)	Inconnu
 	PresentationFramework.dll!System.Windows.Controls.Control.MeasureOverride(System.Windows.Size constraint)	Inconnu
 	PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize)	Inconnu
 	PresentationCore.dll!System.Windows.UIElement.Measure(System.Windows.Size availableSize)	Inconnu
 	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 bool hasAnyContainerSpanChanged, 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 long scrollGeneration, 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)	Inconnu
 	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)	Inconnu
 	PresentationFramework.dll!System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(System.Windows.Size constraint)	Inconnu
 	PresentationFramework.dll!System.Windows.FrameworkElement.MeasureCore(System.Windows.Size availableSize)	Inconnu

I have a fairly good repro:

• open this binlog.
• search for “ReferenceCopyLocalPaths”
  
• select the last item in the results tree
• hit the “Down Key” (it’s the last item so it should have no effect)

NB: the text scaling is at 125%

[SamBent]

The fix is in the pipeline of review/approval/packaging/testing for inclusion in a .NET servicing update. If no problems arise, it should appear early in 2021. I’ll post back to this thread when that happens.

[SamBent]

Thanks for the reminder.

The fix was released in the .NET Update Preview on Jan 26, and in the .NET Update on Feb 9. The former is available for download, the latter is part of the monthly Windows Update payload. (The KB number depends on which OS version you’re running.)