Fill all the screen with StackLayout

Question

I have a StackLayout coded like this:

StackLayout mainStackLayOut = new StackLayout{
    BackgroundColor = Color.Blue,
    //VerticalOptions = LayoutOptions.FillAndExpand,
    //WidthRequest = width,
    HorizontalOptions = LayoutOptions.FillAndExpand,
    Orientation = StackOrientation.Vertical
};

But I want the StackLayout to fill all the screen width and height, also I have tree buttons added like this:

StackLayout buttonsStackLayOut = new StackLayout
{
    BackgroundColor = Color.White,
    //VerticalOptions = LayoutOptions.Fill,
    HorizontalOptions = LayoutOptions.Fill,
    Orientation = StackOrientation.Horizontal,
    Spacing = 0
};
mainStackLayOut.Children.Add(buttonsStackLayOut);


Image doctorImage = new Image
{
    WidthRequest = width / 3,
    HeightRequest = 50,
    BackgroundColor = Color.Gray,
    Source = ImageSource.FromFile ("about.png")
};
buttonsStackLayOut.Children.Add(doctorImage);

How can I fill all the screensize?

Solution

In the most simple form I have managed to achieve what you require.

I set the content of the screen to the main stack layout.

        var mainStackLayout = new StackLayout { BackgroundColor = Color.Blue};
        var buttonsStackLayout = new StackLayout { BackgroundColor = Color.White, Orientation = StackOrientation.Horizontal , Spacing = 0 };

        Image about = new Image { HeightRequest = 50, Source = ImageSource.FromFile("about.jpg") };
        Image twitter = new Image { HeightRequest = 50, Source = ImageSource.FromFile("twitter.jpg") };
        Image refresh = new Image { HeightRequest = 50, Source = ImageSource.FromFile("refresh.jpg") };

        buttonsStackLayout.Children.Add(about);
        buttonsStackLayout.Children.Add(twitter);
        buttonsStackLayout.Children.Add(refresh);

        mainStackLayout.Children.Add(buttonsStackLayout);
        this.Content = mainStackLayout;