Case.xaml

<UserControl x:Class="_2048.Case"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Rectangle Name="background" Fill="{Binding Path=backColor, UpdateSourceTrigger=PropertyChanged}" Stretch="Fill" Stroke="{DynamicResource {x:Static SystemColors.AppWorkspaceBrushKey}}" Margin="3,0,0,0" RadiusX="10" RadiusY="10" StrokeThickness="10"></Rectangle>
        <Label Content="{Binding Path=val, UpdateSourceTrigger=PropertyChanged}" Name="Value" FontSize="80" FontWeight="Bold" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>

</UserControl>