ProductTest/WpfAppProduct/MainWindow.xaml

<Window x:Class="WpfAppProduct.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfAppProduct"
        mc:Ignorable="d"
        Title="MainWindow" MinHeight="450" MinWidth="800" MaxHeight="900" MaxWidth="1600">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition Height="5*"/>
        </Grid.RowDefinitions>
        <TextBlock Text="Продуктовый магазин" FontSize="26" HorizontalAlignment="Center" VerticalAlignment="Center"/>
        <Frame Grid.Row="1" Name="frameL" NavigationUIVisibility="Hidden"/>
    </Grid>
</Window>