ThemedDataGrid not virtualizing when grouping

WPF Studio, Themes, and Shared Library for WPF Forum

Posted 9 years ago by Bjørnar Sundsbø - Norway
Version: 14.2.0620


Not sure if this is the right forums, but we are attempting to use the ThemedDataGrid control with grouping. It appears that virtualization doesn't work when grouped. Checking the DataGridControl from the framework, virtualization works, but of course there is no theme.

AreNativeThemesEnabled="false" does not make a difference, as indicated in a previous post related to ListBox.

Bjørnar Sundsbø

Comments (2)

Posted 9 years ago by Actipro Software Support - Cleveland, OH, USA

Hi Bjørnar,

Looking at our styles compared to the default ones, I don't see anything that particularly stands out as preventing virtualization.  Can you make a new simple sample project that shows the issue (perhaps comparing both) and then email that to our support address?  Then we can debug with that to see if we can determine what the difference is.  Please reference this thread in your email and rename the .zip file extension so it doesn't get spam blocked.  Thanks!

Also if you wish to look into it on your own, all the source for our extensions is up on Codeplex (  If you spot anything there that needs changed, please email us.

Actipro Software Support

Answer - Posted 9 years ago by Actipro Software Support - Cleveland, OH, USA

Thanks for the sample.  There was one Trigger difference in the main DataGrid Style that we have here.  In the real style, which more recently targets .NET 4.5, they have this Style trigger at the end:

			<Condition Property="IsGrouping" Value="true" />
			<Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false" />
		<Setter Property="ScrollViewer.CanContentScroll" Value="false"/>

That VirtualizingPanel.IsVirtualizingWhenGrouping property was added in .NET 4.5.  Since our add-on still targets .NET 4.0, we can't reference it so you would need to clone the Style we provide in the open source there and adjust the Style trigger.  Put the updated implicit Style in your app's Resources.  That will get it working properly.

Actipro Software Support

The latest build of this product (v24.1.2) was released 2 months ago, which was after the last post in this thread.

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