Question

Is there a workaround for the missing x:Shared MarkupExtension in silverlight?

I have the following Xaml which is creating an ellipse on each target series. I need the ellipses to be unique as they are later added to canvas. By using this Xaml I get the error that the UIElement has already been added to another parent (e.g. single Ellipse instance added to Canvas multiple times).

In WPF I simply use the x:Shared property on this style to get it to work.

    <!-- Set the style for the series -->
    <Style TargetType="SciChart:FastLineRenderableSeries" >
        <Setter Property="SeriesColor" Value="#FF93F2C1"/>
        <Setter Property="ResamplingMode" Value="Mid"/>
        <Setter Property="RolloverMarker">
            <Setter.Value>
                <Ellipse Width="9" Height="9" Fill="#7793F2C1" Stroke="#FFA3FFC9"/>
            </Setter.Value>
        </Setter>
    </Style>

A workaround I considered was to create a control called RolloverMarker and set its control template. I’d appreciate any direct or indirect solutions to this problem.

Answer 1

If you are dynamically adding objects to a panel, then a new object needs to be created each time, or you need to define your control in some kind of Template and add a new data object which will use the Template. You cannot add the same item multiple times.

For example,

// Does not work
var templateItem = new FastLineRenderableSeries();
myCanvas.Add(templateItem);
myCanvas.Add(templateItem);


// Works
myCanvas.Add(new FastLineRenderableSeries());
myCanvas.Add(new FastLineRenderableSeries());

Or

<ItemsControl ItemsSource="{Binding SomeCollection}"
              ItemTemplate="{StaticResource FastLineRenderableSeriesStyle}">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <Canvas />
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
</ItemsControl>

// Add items. They'll get rendered with defined ItemStyle.
var templateItem = new FastLineRenderableSeries();
SomeCollection.Add(templateItem);
SomeCollection.Add(templateItem);