Question

I have 2 custom controls as defined below:

public class Icon : Control
{
    public Icon()
        : base()
    {
        DefaultStyleKey = typeof(Icon);
    }

    public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(SolidColorBrush), typeof(Icon), new PropertyMetadata(new SolidColorBrush(Colors.Red)));
    public SolidColorBrush Color
    {
        get
        {
            return (SolidColorBrush)GetValue(ColorProperty);
        }
        set
        {
            SetValue(ColorProperty, value);
        }
    }
}

public class Rating : Control
{
    private StackPanel _panel;

    public Rating()
        : base()
    {
        DefaultStyleKey = typeof(Rating);
    }

    public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("ColorProperty", typeof(SolidColorBrush), typeof(Rating), null);
    public SolidColorBrush Color
    {
        get
        {
            return (SolidColorBrush)GetValue(ColorProperty);
        }
        set
        {
            SetValue(ColorProperty, value);
            Debug.WriteLine(Name + " - Set Color");
        }
    }

    public override void OnApplyTemplate()
    {
        Debug.WriteLine(Name + " - On Apply Template");
        base.OnApplyTemplate();
    }
}

The UI for those controls are defined in a Generic.xaml:

<Style TargetType="lib:Icon">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="lib:Icon">
                <Ellipse Width="32" Height="32" Margin="4" Fill="{Binding Path=Color, RelativeSource={RelativeSource TemplatedParent}}"/>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style TargetType="lib:Rating">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="lib:Rating">
                <StackPanel x:Name="Panel" Orientation="Horizontal">
                    <lib:Icon Color="{Binding Path=Color, RelativeSource={RelativeSource TemplatedParent}}"/>
                    <lib:Icon Color="{Binding Path=Color, RelativeSource={RelativeSource TemplatedParent}}"/>
                    <lib:Icon Color="{Binding Path=Color, RelativeSource={RelativeSource TemplatedParent}}"/>
                    <lib:Icon Color="{Binding Path=Color, RelativeSource={RelativeSource TemplatedParent}}"/>
                    <lib:Icon Color="{Binding Path=Color, RelativeSource={RelativeSource TemplatedParent}}"/>
                </StackPanel>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Now in my MainPage.xaml, i use the Rating control as follows:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
    <StackPanel Orientation="Horizontal" Grid.Row="0">
        <Button Content="Yellow" Click="ChangeDataContext"/>
    </StackPanel>
    <StackPanel Grid.Row="1">
        <lib:Rating Color="Red"/>
        <lib:Rating Name="MyRating" Color="{Binding Path=Color}"/>
    </StackPanel>
</Grid>

In the code-behind, i set the data-context as follows:

public partial class MainPage : PhoneApplicationPage
{
    public MainPage()
    {
        InitializeComponent();
        ColorData data = new ColorData() { Color = new SolidColorBrush(Colors.Cyan) };
        MyRating.DataContext = data;
    }

    private void ChangeDataContext(object sender, System.Windows.RoutedEventArgs e)
    {
        ColorData data = new ColorData() { Color = new SolidColorBrush(Colors.Yellow) };
        MyRating.DataContext = data;
    }
}

public class ColorData
{
    public SolidColorBrush Color { get; set; }
}

When i run this code, i receive AG_E_PARSER_BAD_PROPERTY_VALUE pointing to the Data-binding line in the MainPage.XAML.
Would someone know why this is so and how i can fix that?

Thanks

Answer 1

You’ve registered the wrong name for your Color property. Change

public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("ColorProperty", typeof(SolidColorBrush), typeof(Rating), null);

to

public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(SolidColorBrush), typeof(Rating), null);

and it should work.