---

<Window x:Class="primeapp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Учет посетителей спортивного клуба"
        Height="500"
        Width="950"
        WindowStartupLocation="CenterScreen">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="70"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <Border Background="#FFEAEAEA" Grid.Row="0">
            <StackPanel Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center">
                <Button Content="Клиенты"
                        Width="150"
                        Height="35"
                        Margin="10"
                        Click="ClientsBtn_Click"/>

                <Button Content="Тренеры"
                        Width="150"
                        Height="35"
                        Margin="10"
                        Click="TrainersBtn_Click"/>

                <Button Content="Запись на тренировку"
                        Width="180"
                        Height="35"
                        Margin="10"
                        Click="BookingBtn_Click"/>
            </StackPanel>
        </Border>

        <Frame x:Name="MainFrame"
               Grid.Row="1"
               NavigationUIVisibility="Hidden"/>
    </Grid>
</Window>





using System.Windows;
using primeapp.Database;
using primeapp.Pages;

namespace primeapp
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            FrameObj.frameObj = MainFrame;
            MainFrame.Navigate(new ClientsPage());
        }

        private void ClientsBtn_Click(object sender, RoutedEventArgs e)
        {
            MainFrame.Navigate(new ClientsPage());
        }

        private void TrainersBtn_Click(object sender, RoutedEventArgs e)
        {
            MainFrame.Navigate(new TrainersPage());
        }

        private void BookingBtn_Click(object sender, RoutedEventArgs e)
        {
            MainFrame.Navigate(new BookingPage());
        }
    }
}