[SOLVED] WPF Ribbon ToolTip flickers

Issue

I have a very strange behavior on my Tooltips that are associated with dropdown items.

I’ve posted a video because it’s easier to see
https://imgur.com/a/RxFvAPP

My XAML looks something like this

 <RibbonGroup x:Name="PageRibbonGroup" Header="{x:Static p:Resources.Page_Ribbon_Group}" LargeImageSource="{svgc:SvgImage Source='pack://application:,,,/Resources/HomeTab/Page/page_group.svg'}">
                        <RibbonComboBox>
                            <RibbonGallery x:Name="PagesListComboboxGallery" SelectedItem="{Binding XPath=.}" MaxColumnCount="1">
                                <RibbonGalleryCategory  x:Name="PagesListComboboxGalleryCategory" ItemsSource="{Binding}"/>
                                <RibbonGallery.ToolTip>                                       
                                    <ToolTip Placement="Bottom" Content="ASDF" ToolTipService.ShowDuration="5000"/>
                                </RibbonGallery.ToolTip>
                            </RibbonGallery>
                        </RibbonComboBox>
 </RibbonGroup>

This happens from what I see on every tooltip that is on an Element that is in a dropdown.

I can’t find a reason on why this is happening.

I’ve also created a repo
https://github.com/SebiCiuca/RibbonToolTipFlicker

For combobox and dropdown button you can reproduce this behavior, but for Button3 the Tooltip works fine.

Solution

https://github.com/dotnet/wpf/pull/6063/files

Looks like a WPF Bug, that should be fixed in future .NET6 releases.

This behavior does not reproduce in .NET5.

Answered By – CiucaS

Answer Checked By – Marilyn (BugsFixing Volunteer)