The layout for the MainPage is defined in the MainPage.xaml file. This file contains the XAML markup that defines the layout of the application.
<Page x:Class="Counter.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Counter"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel HorizontalAlignment="Center"
VerticalAlignment="Center">
<TextBlock AutomationProperties.AutomationId="HelloTextBlock"
Text="Hello Uno Platform"
HorizontalAlignment="Center" />
</StackPanel>
</Page>