检查日期是否为节假日并更改日历wpf中的前景

Question

嗨，我想检查日期是否是假日，并更改日期前景 这是我的日历样式

<Style x:Key="CalendarDayButtonStyle" TargetType="primitives:CalendarDayButton">
        <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
        <Setter Property="controls:HolidayHelper.Date" Value="{Binding}" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="primitives:CalendarDayButton">
                    <controls:SimplePanel>
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                               ...
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Rectangle RadiusX="16" RadiusY="16" x:Name="TodayBackground" Fill="{DynamicResource DangerBrush}" Opacity="0"/>
                        <Rectangle x:Name="SelectedBackground" Fill="{DynamicResource PrimaryBrush}" Opacity="0" RadiusY="16" RadiusX="16"/>
                        <ContentPresenter x:Name="NormalText" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
                            <ContentPresenter.Resources>
                                <Style TargetType="{x:Type ContentPresenter}">
                                    <Setter Property="TextElement.Foreground" Value="#212121"/>
                                    <Style.Triggers>
                                        <Trigger Property="controls:HolidayHelper.IsHoliday" Value="True">
                                            <Setter Property="TextElement.Foreground" Value="Red"/>
                                        </Trigger>
                                    </Style.Triggers>
                                </Style>
                            </ContentPresenter.Resources>
                        </ContentPresenter>
                    </controls:SimplePanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

这是我的课程

  private static bool CheckIsHoliday(DateTime date)
            {

                return true;

            }

完整的课程代码是here（最新发布）

我使用了这些代码，但没有任何反应