xhwkclient/XHWK.WKTool/MinToolbar.xaml

<Window x:Class="XHWK.WKTool.MinToolbar"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:XHWK.WKTool"
        mc:Ignorable="d"
        Title="MinToolbar" Height="50" Width="20" AllowsTransparency="True" 
        Topmost="True"
    ShowInTaskbar="False"
    WindowStyle="None" Margin="0" Left="0" Top="0">
    <Window.Background>
        <SolidColorBrush Opacity="0" Color="#00000000" />
    </Window.Background>
    <Viewbox>
        <Grid>
            <Border Background="White" CornerRadius="3">
                <Button x:Name="buttonMin" Height="25" Width="3"
                        Margin="0.5"  Style="{StaticResource {x:Static ToolBar.ButtonStyleKey}}"
                        MouseEnter="buttonMin_MouseEnter">
                    <Button.Template>
                        <ControlTemplate TargetType="{x:Type Button}">
                            <Border
                                BorderBrush="{TemplateBinding Control.BorderBrush}"
                                BorderThickness="0"
                                CornerRadius="3">
                                <Border.Background>#2d8cf0</Border.Background>
                                <ContentPresenter
                                    HorizontalAlignment="Center"
                                    VerticalAlignment="Center"
                                    Content="{TemplateBinding ContentControl.Content}" />
                            </Border>
                        </ControlTemplate>
                    </Button.Template>
                </Button>
            </Border>
            
        </Grid>
    </Viewbox>
</Window>