Q:

Writing a custom control in Windows 8 Metro

I'm writing my first custom user control against WinRT, and I've run into a problem.
I would like to expose an image, PART_NwBadge and it's visibility as Dependency Properties in my control. Then I would like to supply default values through setters in the style. This part is not working. Instead, the default value from the DependencyProperty (in BadgedButton.cs) is being applied.
Is it even possible to do what I've described? Or should I be setting the default values in the C# code? If I do need to set the values in the C# code, would someone comment on how to load image resources in code? After a great deal of searching I've yet to find a solution that works. 
Finally, since this is my first serious attempt at writing a custom control, please suggest any improvements I could make, even if they are not directly related to the problem.
Windows 8 Consumer Preview
C#/WinRT/Metro
Visual Studio 11 Beta
Themes/Generic.xaml
<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:l="using:InkSdkTestApplication.Controls">

    <Style TargetType="l:BadgedButton">
        <Setter Property="Width" Value="36"/>
        <Setter Property="Height" Value="36"/>
        <Setter Property="Background" Value="#1C1C1C"/>
        <Setter Property="BorderBrush" Value="White"/>
        <Setter Property="BorderThickness" Value="2"/>
        <Setter Property="NwBadge">
            <Setter.Value>
                <Image Width="16" Height="16" Source="../Assets/mouse_16x16.png"/>            
            </Setter.Value>
        </Setter>
        <Setter Property="NwBadgeVisibility" Value="Collapsed"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="l:BadgedButton">
                    <Border x:Name="PART_Border"
                            Width="{TemplateBinding Width}"
                            Height="{TemplateBinding Height}"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">

                        <Grid>
                            <ContentPresenter x:Name="PART_Content"
                                              HorizontalAlignment="Center"
                                              VerticalAlignment="Center"
                                              Content="{TemplateBinding Content}"/>

                            <Image x:Name="PART_NwBadge"
                                   HorizontalAlignment="Left"
                                   VerticalAlignment="Top"
                                   Width="16" Height="16"
                                   Visibility="{TemplateBinding NwBadgeVisibility}"
                                   Source="{TemplateBinding NwBadge}"/>
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

Controls/BadgedButton.cs
namespace InkSdkTestApplication.Controls
{
    public sealed class BadgedButton : Control
    {
        #region // Dependency Properties
        public static DependencyProperty ContentProperty =
            DependencyProperty.Register(
                "Content",
                typeof(FrameworkElement),
                typeof(BadgedButton),
                new PropertyMetadata(null));

        public static DependencyProperty NwBadgeProperty =
            DependencyProperty.Register(
                "NwBadge",
                typeof(Image),
                typeof(BadgedButton),
                new PropertyMetadata(null));

        public static DependencyProperty NwBadgeVisibilityProperty =
            DependencyProperty.Register(
                "NwBadgeVisibility",
                typeof(Visibility),
                typeof(BadgedButton),
                new PropertyMetadata(Visibility.Visible));
        #endregion

        #region // Public Properties
        public FrameworkElement Content
        {
            get { return (FrameworkElement)GetValue(ContentProperty); }
            set { SetValue(ContentProperty, value); }
        }

        public Image NwBadge
        {
            get { return (Image)GetValue(NwBadgeProperty); }
            set { SetValue(NwBadgeProperty, value); }
        }

        public Visibility NwBadgeVisibility
        {
            get { return (Visibility)GetValue(NwBadgeVisibilityProperty); }
            set { SetValue(NwBadgeVisibilityProperty, value); }
        }
        #endregion

        public BadgedButton()
        {
            this.DefaultStyleKey = typeof(BadgedButton);
        }
    }
}

A:

http://timheuer.com/blog/archive/2012/03/07/creating-custom-controls-for-metro-style-apps.aspx

