Add project files.

formRegistration.xaml.cs

@@ -0,0 +1,53 @@
+using System.Windows;
+using Npgsql;
+
+namespace SportsTrainingApp
+{
+
+    public partial class formRegistration : Window
+    {
+        public formRegistration()
+        {
+            InitializeComponent();
+        }
+
+        private void Button_Click_ShowPass(object sender, RoutedEventArgs e)
+        {
+            MessageBox.Show($"Ваш пароль: {passwordBox.Password}");
+        }
+
+        private void Button_Click_Cancel(object sender, RoutedEventArgs e)
+        {
+            this.Close();
+        }
+
+        private void Button_Click_OK(object sender, RoutedEventArgs e)
+        {
+            if (loginBox.Text == "" || passwordBox.Password == "" || emailBox.Text == "")
+            {
+                MessageBox.Show("Введены не все данные.");
+                return;
+            }
+            CreateUser(loginBox.Text, passwordBox.Password, emailBox.Text);
+            this.Close();
+        }
+
+        private static void CreateUser(string username, string password, string email)
+        {
+            using (var conn = new NpgsqlConnection(formMain.connectionString))
+            {
+                conn.Open();
+
+                using (var cmd = new NpgsqlCommand("INSERT INTO dbo.users (username, email, password_hash) " +
+                    "VALUES (@username, @email, dbo.crypt(@password, dbo.gen_salt('bf')))", conn))
+                {
+                    cmd.Parameters.AddWithValue("username", username);
+                    cmd.Parameters.AddWithValue("email", email);
+                    cmd.Parameters.AddWithValue("password", password);
+                    cmd.ExecuteNonQuery();
+                }
+            }
+            MessageBox.Show("Пользователь создан!");
+        }
+    }
+}