vStationURM/Tools/SonopostSearchTool/LoadingMask.xaml

<UserControl x:Class="SonopostSearchTool.LoadingMask"
             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" 
             IsVisibleChanged="HandleVisibleChanged">
    <UserControl.Background>
        <SolidColorBrush Color="Black" Opacity="0.2"  />
    </UserControl.Background>
    <UserControl.Resources>
        <SolidColorBrush Color="#FF007BE5" x:Key="CirclesColor" />
    </UserControl.Resources>

    <Viewbox Width="100" Height="100"  
            HorizontalAlignment="Center"  
            VerticalAlignment="Center">
        <Grid x:Name="LayoutRoot"   
                Background="Transparent"  
                HorizontalAlignment="Center"  
                VerticalAlignment="Center">
            <TextBlock Text="{DynamicResource Loading}"  HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="14" Foreground="White" FontWeight="Bold" />
            <Canvas RenderTransformOrigin="0.5,0.5"  
                    HorizontalAlignment="Center"  
                    VerticalAlignment="Center" Width="120"  
                    Height="120" Loaded="HandleLoaded"  
                    Unloaded="HandleUnloaded"  >
                <Ellipse x:Name="C0" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="1.0"/>
                <Ellipse x:Name="C1" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.9"/>
                <Ellipse x:Name="C2" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.8"/>
                <Ellipse x:Name="C3" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.7"/>
                <Ellipse x:Name="C4" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.6"/>
                <Ellipse x:Name="C5" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.5"/>
                <Ellipse x:Name="C6" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.4"/>
                <Ellipse x:Name="C7" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.3"/>
                <Ellipse x:Name="C8" Width="20" Height="20"  
                         Canvas.Left="0"  
                         Canvas.Top="0" Stretch="Fill"  
                         Fill="{StaticResource CirclesColor}" Opacity="0.2"/>
                <Canvas.RenderTransform>
                    <RotateTransform x:Name="SpinnerRotate"  
                         Angle="0" />
                </Canvas.RenderTransform>
            </Canvas>
        </Grid>
    </Viewbox>
</UserControl>