FinalPresenceLexa/Presence/MainWindow.axaml.cs

using Avalonia.Controls;
using System;

namespace Presence
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            BtnOpenGroups.Click += BtnOpenGroups_Click;
            BtnOpenStudents.Click += BtnOpenStudents_Click;
            BtnOpenAttendance.Click += BtnOpenAttendance_Click;
        }

        private void BtnOpenGroups_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
        {
            var window = new GroupsWindow();
            window.Show();
        }

        private void BtnOpenStudents_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
        {
            var window = new StudentsWindow();
            window.Show();
        }
        
        private void BtnOpenAttendance_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
        {
            var window = new AttendanceWindow();
            window.Show();
        }
    }
}