FloatingStatusWindow/FloatingStatusWindowLibrary/MainWindow.xaml

<windows:SnappingWindow x:Class="FloatingStatusWindowLibrary.MainWindow"
                        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                        xmlns:htmlLabelControl="clr-namespace:Common.Wpf.HtmlLabelControl;assembly=Common.Wpf"
                        xmlns:windows="clr-namespace:Common.Wpf.Windows;assembly=Common.Wpf"
                        windows:ControlBox.HasMaximizeButton="False"
                        windows:ControlBox.HasMinimizeButton="False"
                        windows:ControlBox.HasSystemMenu="False"
                        Title="FloatingStatusWindow"
                        Height="250"
                        Width="400"
                        WindowStyle="None"
                        AllowsTransparency="True"
                        ResizeMode="CanResize"
                        Background="Transparent"
                        ShowInTaskbar="False"
                        x:ClassModifier="internal">

    <Border Name="BorderFull"
            BorderThickness="4,0,4,4"
            Background="Transparent"
            Margin="0">
        <Grid Background="Transparent">
            <Border Name="HeaderBorder"
                    Height="24"
                    VerticalAlignment="Top">
                <Grid>
                    <Label HorizontalAlignment="Stretch"
                           Name="HeaderLabel"
                           Margin="0,0,0,0"
                           HorizontalContentAlignment="Center"
                           VerticalContentAlignment="Center"
                           Padding="0">
                    </Label>
                    <Button Height="18"
                            Width="18"
                            HorizontalAlignment="Right"
                            Margin="0,0,5,0"
                            Click="HandleChangeAppearanceClick"
                            WindowChrome.IsHitTestVisibleInChrome="True"
                            Content="&#xE115;"
                            FontFamily="Segoe UI Symbol"
                            FontSize="12"
                            Padding="0"></Button>
                </Grid>
            </Border>
            <htmlLabelControl:HtmlLabel Name="HtmlLabel"
                                        Foreground="White"
                                        Margin="0,20,0,0" />
        </Grid>
    </Border>
</windows:SnappingWindow>