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musicschoolapp/MainWindow.xaml.cs

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+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Eventing.Reader;
+using System.Linq;
+using System.Management.Instrumentation;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+using System.Windows.Shell;
+using System.Runtime;
+
+namespace musicschoolapp
+{
+    /// <summary>
+    /// Логика взаимодействия для MainWindow.xaml
+    /// </summary>
+    public partial class MainWindow : Window
+    {
+       
+        public MainWindow()
+        {
+            InitializeComponent();
+        }
+
+        private async void registerButton_Click(object sender, RoutedEventArgs e)
+        {
+            await executeDB(usernameTextBox.Text, passwordBox.Password, true);
+        }
+
+        private async void loginButton_Click(object sender, RoutedEventArgs e)
+        {
+            
+            await executeDB(usernameTextBox.Text, passwordBox.Password, false);
+            
+
+            //await DbHandlerAsync();
+
+        }
+        //async Task DbHandlerAsync()
+        //{
+        //    await executeDB(usernameTextBox.Text, passwordBox.Password);
+        //}
+        static async Task<bool> executeDB(string login, string password, bool isreg)
+        {
+            musicschoolEntities1 musicschoolEntities = new musicschoolEntities1();
+            string[] strings = new string[] { login, password };
+            var isunique = from s in musicschoolEntities.User where s.username == login select s;
+            if (string.Join("", strings) != String.Empty)
+            {
+                var query = from s in musicschoolEntities.User where s.username == login && s.password == password select s;
+                if (query.Count() > 0 && !isreg)
+                {
+                    MessageBox.Show("Авторизация успешна.");
+
+                    WorkingWindow workingWindow = new WorkingWindow(query.FirstOrDefault());
+                    workingWindow.Show();
+                    return true;
+                }
+                else
+                {
+                    if (isreg && isunique.Count() == 0)
+                    {
+                        User user = new User();
+                        user.username = login;
+                        user.password = password;
+                        musicschoolEntities.User.Add(user);
+                        musicschoolEntities.SaveChanges();
+                        MessageBox.Show("Регистрация выполнена.");
+                        return true;
+                    }
+                    else if(isunique.Count() > 0)
+                    {
+                        MessageBox.Show("Пользователь уже существует.");
+                        return false;
+                    }
+                    MessageBox.Show("Ошибка логина или пароля.");
+                    return false;
+                }
+            }
+            else
+                MessageBox.Show("заполните все поля!");
+            return false;
+        }
+    }
+}