Where does this blank line come from in this Xamarin Forms ContentPage?

Question

The image below is from a Xamarin Forms application. Notice the white area between the green and red areas. I am trying to figure out where this white area is coming from? I would think the green and red would butt right next to each other.

Here is the code that produces the above. I am using a ControlTemplate which is a requirement for my design (I am using a BoxView to illustrate the issue for this question)...

Base Class - XAML

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="WP.MobileMidstream.Device.Pages.DialogBase"
             Visual="Material"             
             >
    <ContentPage.ControlTemplate>
        <ControlTemplate>
            <StackLayout>
                <BoxView BackgroundColor="Green" />
                <ContentPresenter VerticalOptions="FillAndExpand"
                                  BackgroundColor="Red" />
            </StackLayout>
        </ControlTemplate>
    </ContentPage.ControlTemplate>
</ContentPage>

Base Class - Code behind - notice the Navigation bar is made to not show

[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class DialogBase : ContentPage
{
    public DialogBase()
    {
        InitializeComponent();

        NavigationPage.SetHasNavigationBar(this, false);
    }
}

Page being displayed that extends DialogBase

<?xml version="1.0" encoding="utf-8" ?>
<d:DialogBase xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:d="clr-namespace:WP.MobileMidstream.Device.Pages"
             x:Class="WP.MobileMidstream.Device.Pages.AdjustmentEditPage">
    <ContentPage.Content>
        <StackLayout>
            <Label Text="Welcome to Xamarin.Forms!"
                VerticalOptions="CenterAndExpand" 
                HorizontalOptions="CenterAndExpand" />
        </StackLayout>
    </ContentPage.Content>
</d:DialogBase>

It's the first page shown when the app loads

public partial class App : Application
{
    public App()
    {
        InitializeComponent();

        ContainerRegistration.Register();

        try
        {
            // register main container navigation
            var mainPage = FreshPageModelResolver.ResolvePageModel<AdjustmentEditPageModel>();
            var mainNavigation = new FreshNavigationContainer(mainPage, NavigationContainerNames.DailyRunSheet);
            mainNavigation.BarBackgroundColor = Color.FromRgb(0, 69, 140);
            mainNavigation.BarTextColor = Color.White;

            MainPage = mainNavigation;
        }
        catch (Exception ex)
        {
        }
    }

}

Answer 1

You need to use:

         <StackLayout Spacing="0">
            <BoxView BackgroundColor="Green" />
            <ContentPresenter VerticalOptions="FillAndExpand"
                              BackgroundColor="Red" />
        </StackLayout>