New Post: Extended WPF Toolkit Zoombox NullReferenceException

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
    xmlns:dc="clr-namespace:WPF.JoshSmith.Controls"
    xmlns:local="clr-namespace:MagnifyingAdornerSample"
    mc:Ignorable="d"
    Title="MainWindow" 
    MinHeight="600"
    MinWidth="800"           
    Height="{Binding Source={x:Static SystemParameters.FullPrimaryScreenHeight}}"
    Width="{Binding Source={x:Static SystemParameters.FullPrimaryScreenWidth}}"
    WindowStartupLocation="CenterScreen" >

<Window.Resources>

    <Storyboard x:Key="MarchingAnts">
        <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" 
                                    Storyboard.TargetName="selectionRectangle" 
                                    Storyboard.TargetProperty="(Shape.StrokeDashOffset)" 
                                    RepeatBehavior="Forever">
            <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
            <SplineDoubleKeyFrame KeyTime="00:00:00.5000000" Value="10"/>
        </DoubleAnimationUsingKeyFrames>
    </Storyboard>

</Window.Resources>

<Window.Triggers>
    <EventTrigger RoutedEvent="FrameworkElement.Loaded">
        <BeginStoryboard Storyboard="{StaticResource MarchingAnts}"/>
    </EventTrigger>
</Window.Triggers>


<Grid
        x:Name="findPlateView"
        Visibility="Collapsed">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="9*" />
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition/>
    </Grid.RowDefinitions>

    <xctk:Zoombox x:Name="imgZoomBox" MinScale="0.5" MaxScale="125" Style="{StaticResource myzoom}">
        <Grid Width="{Binding Source={x:Static SystemParameters.FullPrimaryScreenWidth}}" Height="{Binding Source={x:Static SystemParameters.FullPrimaryScreenHeight}}" Background="Transparent">
            <!-- Image with DragCanvas -->
            <!-- The Drag Canvas is stretched to fill its content therefore by sizing it to match the image in code the selection box gets clipped to image size -->
            <Image
                x:Name="findPlateImage" Source="/Shared/sample.jpg"
           Margin="5" SizeChanged="findPlateImage_SizeChanged"/>

            <dc:DragCanvas x:Name="BackPanel" SizeChanged="BackPanel_SizeChanged" Background="Transparent" Visibility="Visible">
                <Rectangle x:Name="selectionRectangle" Width="250" Height="100" HorizontalAlignment="Center" VerticalAlignment="Center">
                    <Rectangle.Style>
                        <Style TargetType="{x:Type Rectangle}">
                            <Setter Property="Stroke" Value="#FFFFFF"/>
                            <Setter Property="StrokeDashArray" Value="5"/>
                            <Setter Property="StrokeDashOffset" Value="0"/>
                            <Setter Property="StrokeThickness" Value="3"/>
                            <Setter Property="Fill" Value="#14FFFFFF" />
                            <!-- <Setter Property="Fill" Value="Yellow"/>
                            <Setter Property="Opacity" Value="0.2"/> -->
                        </Style>
                    </Rectangle.Style>
                </Rectangle>
            </dc:DragCanvas>


        </Grid>
    </xctk:Zoombox>



</Grid>