Issue displaying Canvas in Viewbox across multiple UserControls

Question

UPDATE: Apparently I have to set x:Shared to False on my Canvas elements in App.xaml.

I have some Canvas elements set as StaticResources in App.xaml that draw various icons. I also have a custom UserControl that simply displays a Button whose content is a Viewbox with a ContentPresenter where I then set a StaticResource.

For example...

    <Button>
        <Viewbox Margin="4">
            <ContentPresenter Content="{StaticResource ResourceKey=IconAdd}" />
        </Viewbox>
    </Button>

This works as expected if I have just 1 instance of the UserControl, but if I put multiple instances only the last one actually draws the Canvas icon. Any ideas why?

For example...

<StackPanel>

<controls:MyUserControlButton /> <!-- No icon -->
<controls:MyUserControlButton /> <!-- No icon -->
<controls:MyUserControlButton /> <!-- Shows icon -->

</StackPanel>

Thanks!

Answer 1

Welcome to our Microsoft Q&A platform!

I think you better use Grid instead of Stackpanel.

 <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <controls:MyUserControlButton Grid.Row="0"/>
        <controls:MyUserControlButton Grid.Row="1"/>
        <controls:MyUserControlButton Grid.Row="2"/>
    </Grid>

Thanks.

Answer 2

I have the same issue. It looks like a bug. The icon is only shown in the last TreeViewItem for me. When I expand, it always moves it to the lower level.