How can I set the FontSize of the header in Calendar View using WinUI3?

Question

I want to expand the size of the Header section.

 <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
        <CalendarView
            Width="600"
            Height="600"
            DayItemFontSize="40"
            FirstOfMonthLabelFontSize="40"
            FirstOfYearDecadeLabelFontSize="40"
            MonthYearItemFontSize="40"
            FontSize="40"
            >
        </CalendarView>
    </StackPanel>

I have tried adjusting almost all Set Size options, but I still can't find which one can change the size of the header

Answer 1

There's no direct way to do this. Let me show you an example using the FindDescendants() extension method from the CommunityToolkit.WinUI.UI NuGet package.

private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
    SetHeaderButtonFontSize(40);
    SetWeekDayNamesFontSize(40);
}

private void SetHeaderButtonFontSize(double fontSize)
{
    if (this.CalendarViewControl
        .FindDescendants()
        .OfType<Button>()
        .Where(x => x.Name == "HeaderButton")
        .FirstOrDefault() is not Button headerButton)
    {
        return;
    }

    headerButton.FontSize = fontSize;
}

private void SetWeekDayNamesFontSize(double fontSize)
{
    if (this.CalendarViewControl
        .FindDescendants()
        .OfType<Grid>()
        .Where(x => x.Name == "WeekDayNames")
        .FirstOrDefault() is not Grid weekDayNamesGrid)
    {
        return;
    }

    foreach (TextBlock child in weekDayNamesGrid.Children.OfType<TextBlock>())
    {
        child.FontSize = fontSize;
    }
}