Unable to modify Style of Expander

[melsawy93]

I am trying to modify the icon in the expander like the demo but its not working for me:

xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"

<Expander IsExpanded="True">
    <Expander.Style>
        <Style BasedOn="{StaticResource MaterialDesignExpander}" TargetType="Expander">
            <Setter Property="materialDesign:ExpanderAssist.ExpanderButtonContent" Value="{materialDesign:PackIcon Kind=Plus}" />
            <Style.Triggers>
                <Trigger Property="IsExpanded" Value="True">
                    <Setter Property="materialDesign:ExpanderAssist.ExpanderButtonContent" Value="{materialDesign:PackIcon Kind=Minus}" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </Expander.Style>

I am getting: XDG0012 The member "ExpanderButtonContent" is not recognized or is not accessible.

Any pointers?

[longkimkao]

did you solve it ?

[Keboo]

This looks like it was likely caused because the ExpanderButtonContent was new and introduced on Aug 16 2023, but the 5.0.0 NuGet had not been released yet. With the release of 5.0.0 the above code does appear to work for me.