I used Mike Swanson's illustrator to xaml converter to convert some of my images to xaml. The convert creates a viewbox that contains the image. These viewboxes I made resource files in my program.

The code below shows what I'm trying to do: I have a viewmodel that has an enum variable called PrimaryWinding of type Windings. The values PrimD and PrimY of the enum select the respective PrimD and PrimY xaml files in the resources.

<UserControl.Resources>
    <DataTemplate x:Key="PrimTrafo" DataType="{x:Type l:Windings}">
        <Frame Source="{Binding}" x:Name="PART_Image" NavigationUIVisibility="Hidden">
            <Frame.LayoutTransform>
                <ScaleTransform ScaleX="0.5" ScaleY="0.5"/>
            </Frame.LayoutTransform>
        </Frame>
        <DataTemplate.Triggers>
            <DataTrigger Binding="{Binding}" Value="PrimD">
                <Setter TargetName="PART_Image" Property="Source" Value="Resources\PrimD.xaml" />
            </DataTrigger>
            <DataTrigger Binding="{Binding}" Value="PrimY">
                <Setter TargetName="PART_Image" Property="Source" Value="Resources\PrimY.xaml" />
            </DataTrigger>
        </DataTemplate.Triggers>
    </DataTemplate>
</UserControl.Resources>

<!--The contentcontrol that holds the datatemplate defined above-->
<Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="2*"></ColumnDefinition>
        <ColumnDefinition Width="2*"></ColumnDefinition>
        <ColumnDefinition Width="1*"></ColumnDefinition>
    </Grid.ColumnDefinitions>
    <ContentControl Grid.Column="0" Content="{Binding PrimaryWinding}" ContentTemplate="{StaticResource PrimTrafo}"/>
</Grid>

This code works. Only I can't resize the drawings to the size of the grid cell. I added the ScaleTransform class to resize the image.
Is a Frame the wrong class to hold the drawings?
Should I use the ScaleTransform class to resize the drawing to the size of the cell? And how can I do that dynamically?