Add project files.

formMain.xaml.cs

@@ -0,0 +1,26 @@
+using System.Windows;
+
+namespace SportsTrainingApp;
+
+/// <summary>
+/// Interaction logic for MainWindow.xaml
+/// </summary>
+public partial class formMain : Window
+{
+    public const string connectionString = "Host=192.168.0.110:5432;Username=KhasanovAM;Password=Admin123;Database=SportsTrainingApp";
+    public formMain()
+    {
+        InitializeComponent();
+    }
+
+    private void Button_Click_1(object sender, RoutedEventArgs e)
+    {
+        var formLogin = new formLogin(this);
+        formLogin.ShowDialog();
+    }
+
+    private void Button_Click_2(object sender, RoutedEventArgs e)
+    {
+        new formRegistration().ShowDialog();
+    }
+}