覆盖样式触发器中的资源

Question

我有ListBoxItem样式，我使用普通前景和资源＆＃34; GrayBrush2＆＃34;突出显示。 选择后，可以通过样式的触发器和设置器将前景属性更改为白色。但我也想在选择项目时将GrayBrush资源本地覆盖为黑色。

示例代码：

<Style TargetType="ListBoxItem"
           BasedOn="{StaticResource MetroListBoxItem}">
        <!-- This will override the GrayBrush2 Resource with my local Value. 
        I want tos to be only applies when my Item is selected. -->
        <Style.Resources>
            <SolidColorBrush x:Key="GrayBrush2"
                     Color="{StaticResource HighlightColor}" />
        </Style.Resources>
        <Style.Setters>
            <Setter Property="Foreground"
                Value="{DynamicResource BlackBrush}" />
        </Style.Setters>
        <Style.Triggers>
            <Trigger Property="IsSelected"
                 Value="True">
                <Setter Property="Foreground"
                    Value="{DynamicResource WhiteBrush}" />
                <!-- Here I want to apply the resources Part dynamically -->
            </Trigger>
        </Style.Triggers>
    </Style>