ListView Update Extremely Slow When Grouping Is Used

Question

From my understanding, the default ItemsPanel for ListView is VirtualizingStackPanel. When I create a GroupStyle for my list view, the refresh rate is terrible. Based on comments in this post

WPF ListView Very Slow Performance - Why? (ElementHost, or Other Reason?)

GroupStyle overrides the default VirtualStackPanel with StackPanel. I have explicitly declared a VirutalzingStackPanel as my ListView's ItemsPanel, but performance is still bad. Why is grouping so slow? More than likely there is something going on with grouping I don't understand.

Answer 1

As the author of the post below mentions

In a normal WPF ItemsControl that virtualizes, such as ListBox or ListView, virtualization turns off when you turn grouping on. This sample shows how to achieve the same visual look of grouping and much of the same API while still having virtualization.

Have a look at this solution developed in the sample project. However, not an easy or straight forward method at all.

Grouping and Virtualization

Remember that this method is suggested for .NET 4.0 and earlier. I believe there are new methods introduced in the .NET 4.5 which deal with this situation such as VirtualizingPanel.IsVirtualizingWhenGrouping property. However I haven't tested this since I don't have an access to .NET 4.5 atm.

VirtualizingPanel.IsVirtualizingWhenGrouping Attached Property

Gets or sets a value that indicates whether this VirtualizingPanel virtualizes the items in its collection when it displays groups.