SHJX_GM/SHJX.Service.Library/CustomControl/Resources/TooltipStyle.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style TargetType="ToolTip">
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="UseLayoutRounding" Value="True" />
        <Setter Property="Background" Value="Black" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ToolTip">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                            UseLayoutRounding="{TemplateBinding UseLayoutRounding}">
                        <ContentPresenter />
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>