Потихоньку исправляем структуру под MVVM.

App.xaml

@@ -1,8 +1,6 @@
 <Application x:Class="EmployeeManager.App"
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
-             xmlns:local="clr-namespace:EmployeeManager"
-             StartupUri="View/MainWindow.xaml">
     <Application.Resources>
         <!-- Стиль для закругленных кнопок -->
         <Style x:Key="RoundedButtonStyle" TargetType="Button">

App.xaml.cs

@@ -1,4 +1,8 @@
-using System.Configuration;
+using EmployeeManager.Model.Data;
+using EmployeeManager.View;
+using EmployeeManager.ViewModel;
+using Microsoft.Extensions.DependencyInjection;
+using System.Configuration;
 using System.Data;
 using System.Windows;
 
@@ -9,6 +13,32 @@ namespace EmployeeManager
     /// </summary>
     public partial class App : Application
     {
+        public IServiceProvider ServiceProvider { get; private set; }
+
+        protected override void OnStartup(StartupEventArgs e)
+        {
+            var services = new ServiceCollection();
+
+            // Регистрация DbContext
+            services.AddDbContext<ApplicationConext>();
+
+            // Регистрация сервисов
+            services.AddScoped<IPhysicalPersonService, PhysicalPersonService>();
+
+            // Регистрация ViewModel
+            services.AddTransient<DataManageViewModel>();
+
+            // Регистрация окон
+            services.AddTransient<MainWindow>();
+
+            // Создаем ServiceProvider
+            ServiceProvider = services.BuildServiceProvider();
+
+            // Открываем главное окно
+            var mainWindow = ActivatorUtilities.CreateInstance<MainWindow>(ServiceProvider);
+            mainWindow.Show();
+        }
+
     }
 
 }

Model/DataWorker.cs

@@ -1,113 +1,80 @@
-using EmployeeManager.Model.Data;
+using EmployeeManager.Model;
+using EmployeeManager.Model.Data;
 using System.Data.Common;
 using System.Linq;
 
-namespace EmployeeManager.Model
+public interface IPhysicalPersonService
 {
-    public static class DataWorker
+    List<PhysicalPerson> GetAllPhysicalPersons();
+    string CreatePhysicalPerson(PhysicalPersonDto personDto);
+    string EditPhysicalPerson(int id, PhysicalPersonDto updatedData);
+    string DeletePhysicalPerson(int id);
+}
+
+public class PhysicalPersonService : IPhysicalPersonService
+{
+    private readonly ApplicationConext _context;
+
+    public PhysicalPersonService(ApplicationConext context)
     {
-        public static string CreatePhysicalPerson(string namePhysicalPersons, string surnamePhysicalPersons, string patronomicPhysicalPersons, DateTime birthday, string gender, string address, string telephone)
+        _context = context;
+    }
+
+    public List<PhysicalPerson> GetAllPhysicalPersons() => _context.PhysicalPersons.ToList();
+
+    public string CreatePhysicalPerson(PhysicalPersonDto personDto)
+    {
+        if (_context.PhysicalPersons.Any(p =>
+            p.NamePhysicalPersons == personDto.Name &&
+            p.SurnamePhysicalPersons == personDto.Surname &&
+            p.Birthday == personDto.Birthday))
         {
-            string result = "Возникла ошибка. Обратитесь в ЛАОД.";
+            return "Физическое лицо уже существует.";
-
-            using(ApplicationConext db = new ApplicationConext())
-            {
-                bool checkIsExist = db.PhysicalPersons.Any(
-                    e => e.NamePhysicalPersons == namePhysicalPersons 
-                    && e.SurnamePhysicalPersons == surnamePhysicalPersons
-                    && e.PatronomicPhysicalPersons == patronomicPhysicalPersons
-                    && e.Birthday == birthday
-                    );
-
-                if (!checkIsExist)
-                {
-                    PhysicalPerson newPhysicalPerson = new PhysicalPerson
-                    {
-                        NamePhysicalPersons = namePhysicalPersons,
-                        SurnamePhysicalPersons = surnamePhysicalPersons,
-                        PatronomicPhysicalPersons = patronomicPhysicalPersons,
-                        Birthday = birthday,
-                        Gender = gender,
-                        Address = address,
-                        Telephone = telephone
-                    };
-                    db.PhysicalPersons.Add(newPhysicalPerson);
-                    db.SaveChanges();
-                    result = "Физическое лицо добавлено.";
-                }
-                return result;
-            }
         }
 
-        public static string CreateEmployee(string nameJob, DateTime startJob, DateTime? endJob, string? partTimeJob, float bid, PhysicalPerson? physicalPersons)
+        var newPerson = new PhysicalPerson
         {
-            string result = "Возникла ошибка. Обратитесь в ЛАОД.";
+            NamePhysicalPersons = personDto.Name,
+            SurnamePhysicalPersons = personDto.Surname,
+            PatronomicPhysicalPersons = personDto.Patronomic,
+            Birthday = personDto.Birthday,
+            Gender = personDto.Gender,
+            Address = personDto.Address,
+            Telephone = personDto.Telephone
+        };
 
-            using (ApplicationConext db = new ApplicationConext())
+        _context.PhysicalPersons.Add(newPerson);
-            {
+        _context.SaveChanges();
+        return "Физическое лицо добавлено.";
+    }
 
-                Employee newEmployee = new Employee
+    public string EditPhysicalPerson(int id, PhysicalPersonDto updatedData)
-                {
+    {
-                    NameJob = nameJob,
+        var person = _context.PhysicalPersons.FirstOrDefault(p => p.Id == id);
-                    StartJob = startJob,
+        if (person == null)
-                    EndJob = endJob,
+            return "Физическое лицо не найдено.";
-                    PartTimeJob = partTimeJob,
-                    Bid = bid,
-                    PhysicalPersonsId = physicalPersons.Id
-                    
-                };
-                db.Employees.Add(newEmployee);
-                db.SaveChanges();
-                result = "Работник добавлен.";
 
-                return result;
+        person.NamePhysicalPersons = updatedData.Name;
+        person.SurnamePhysicalPersons = updatedData.Surname;
+        person.PatronomicPhysicalPersons = updatedData.Patronomic;
+        person.Birthday = updatedData.Birthday;
+        person.Gender = updatedData.Gender;
+        person.Address = updatedData.Address;
+        person.Telephone = updatedData.Telephone;
 
-            }
+        _context.SaveChanges();
-        }
+        return "Данные физического лица обновлены.";
+    }
 
-        public static string DeletePhysicalPerson(PhysicalPerson physicalPerson)
+    public string DeletePhysicalPerson(int id)
-        {
+    {
-            string result = "Возникла ошибка. Обратитесь в ЛАОД.";
+        var person = _context.PhysicalPersons.FirstOrDefault(p => p.Id == id);
+        if (person == null)
+            return "Физическое лицо не найдено.";
 
-            using(ApplicationConext db = new ApplicationConext())
+        _context.PhysicalPersons.Remove(person);
-            {
+        _context.SaveChanges();
-                db.PhysicalPersons.Remove(physicalPerson);
+        return "Физическое лицо удалено.";
-                db.SaveChanges();
-                result = "Физическое лицо удалено.";
-            }
-
-            return result;
-
-        }
-
-        public static string EditPhysicalPerson(PhysicalPerson oldPhysicalPerson, string newNamePhysicalPersons, string newSurnamePhysicalPersons, string newPatronomicPhysicalPersons, DateTime newBirthday, string newGender, string newAddress, string newTelephone)
-        {
-            string result = "Возникла ошибка. Обратитесь в ЛАОД.";
-
-            using (ApplicationConext db = new ApplicationConext())
-            {
-                PhysicalPerson physicalPerson = db.PhysicalPersons.FirstOrDefault(e => e.Id == oldPhysicalPerson.Id);
-                
-                physicalPerson.SurnamePhysicalPersons = newSurnamePhysicalPersons;
-                physicalPerson.NamePhysicalPersons = newNamePhysicalPersons;
-                physicalPerson.PatronomicPhysicalPersons = newPatronomicPhysicalPersons;
-                physicalPerson.Birthday = newBirthday;
-                physicalPerson.Gender = newGender;
-                physicalPerson.Address = newAddress;
-                physicalPerson.Telephone = newTelephone;
-            }
-
-            return result;
-
-        }
-
-        public static List<PhysicalPerson> GetAllPhysicalPerson()
-        {
-            using (ApplicationConext db = new ApplicationConext())
-            {
-                var result = db.PhysicalPersons.ToList();
-                return result;
-            }
-        }
     }
 }
+

Model/PhysicalPersonDto.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace EmployeeManager.Model
+{
+    public class PhysicalPersonDto
+    {
+        public string Name { get; set; }
+        public string Surname { get; set; }
+        public string Patronomic { get; set; }
+        public DateTime Birthday { get; set; }
+        public string Gender { get; set; }
+        public string Address { get; set; }
+        public string Telephone { get; set; }
+    }
+}

View/MainWindow.xaml.cs

@@ -17,10 +17,13 @@ namespace EmployeeManager.View
     /// </summary>
     public partial class MainWindow : Window
     {
-        public MainWindow()
+        private readonly DataManageViewModel _viewModel;
+
+        public MainWindow(DataManageViewModel viewModel) 
         {
             InitializeComponent();
-            DataContext = new DataManageViewModel();
+            _viewModel = viewModel; 
+            DataContext = _viewModel; 
         }
     }
 }

View/PhysicalPerson/AddPhysicalPersonWindow.xaml.cs

@@ -15,15 +15,12 @@ using System.Windows.Shapes;
 
 namespace EmployeeManager.View.PhysicalPerson
 {
-    /// <summary>
-    /// Логика взаимодействия для AddPhysicalPersonWindow.xaml
-    /// </summary>
     public partial class AddPhysicalPersonWindow : Window
     {
         public AddPhysicalPersonWindow()
         {
             InitializeComponent();
-            DataContext = new DataManageViewModel();
+            //DataContext = new DataManageViewModel();
         }
     }
 }

View/PhysicalPerson/PhysicalPersoManagementWindow.xaml.cs

@@ -23,7 +23,7 @@ namespace EmployeeManager.View.PhysicalPerson
         public PhysicalPersoManagementWindow()
         {
             InitializeComponent();
-            DataContext = new DataManageViewModel();
+            //DataContext = new DataManageViewModel();
         }
     }
 }

ViewModel/DataManageViewModel.cs

@@ -12,109 +12,53 @@ namespace EmployeeManager.ViewModel
 {
     public class DataManageViewModel : INotifyPropertyChanged
     {
-        private List<PhysicalPerson> allPhysicalPeoples = DataWorker.GetAllPhysicalPerson();
+        private readonly IPhysicalPersonService _physicalPersonService;
+
+        public DataManageViewModel(IPhysicalPersonService physicalPersonService)
+        {
+            _physicalPersonService = physicalPersonService;
+            AllPhysicalPeoples = _physicalPersonService.GetAllPhysicalPersons();
+        }
+
+        private List<PhysicalPerson> allPhysicalPeoples;
         public List<PhysicalPerson> AllPhysicalPeoples
         {
-            get { return allPhysicalPeoples; }
+            get => allPhysicalPeoples;
             set
             {
                 allPhysicalPeoples = value;
-                NotifyPropertyChanged("AllPhysicalPeoples");
+                NotifyPropertyChanged(nameof(AllPhysicalPeoples));
             }
         }
 
-
+        public string NamePhysicalPersons { get; set; }
-
+        public string SurnamePhysicalPersons { get; set; }
-        public string NamePhysicalPersons { get; set; } = string.Empty;
+        public string PatronomicPhysicalPersons { get; set; }
-        public string SurnamePhysicalPersons { get; set; } = string.Empty;
-        public string PatronomicPhysicalPersons { get; set; } = string.Empty;
         public DateTime Birthday { get; set; }
-        public string Gender { get; set; } = string.Empty;
+        public string Gender { get; set; }
-        public string Address { get; set; } = string.Empty;
+        public string Address { get; set; }
-        public string Telephone { get; set; } = string.Empty;
+        public string Telephone { get; set; }
 
-
+        public RelayCommand AddNewPhysicalPersonCommand => new RelayCommand(obj =>
-
-
-
-        private RelayCommand addNewPhysicalPerson;
-        public RelayCommand AddNewPhysicalPerson
         {
-            get
+            var newPerson = new PhysicalPersonDto
             {
-                return addNewPhysicalPerson ?? new RelayCommand(obj =>
+                Name = NamePhysicalPersons,
-                {
+                Surname = SurnamePhysicalPersons,
-                    string resultStr = "";
+                Patronomic = PatronomicPhysicalPersons,
-
+                Birthday = Birthday,
-                    resultStr = DataWorker.CreatePhysicalPerson(NamePhysicalPersons, SurnamePhysicalPersons, PatronomicPhysicalPersons, Birthday, Gender, Address, Telephone);
+                Gender = Gender,
-                }
+                Address = Address,
-                );
+                Telephone = Telephone
-            }
+            };
-        }
-
-
-
-
-
-        private RelayCommand openPhysicalPersoManagementWindow;
-        public RelayCommand OpenPhysicalPersoManagementWindow
-        {
-            get
-            {
-                return openPhysicalPersoManagementWindow ?? new RelayCommand(obj =>
-                {
-                    OpenPhysicalPersoManagementWindowMethod();
-                }
-                );
-            }
-        }
-
-        private RelayCommand openAddPhysicalPersonWindow;
-        public RelayCommand OpenAddPhysicalPersonWindow
-        {
-            get
-            {
-                return openAddPhysicalPersonWindow ?? new RelayCommand(obj =>
-                {
-                    OpenAddPhysicalPersonWindowMethod();
-                }
-                );
-            }
-        }
-
-
-
-
-        private void OpenPhysicalPersoManagementWindowMethod()
-        {
-            PhysicalPersoManagementWindow newPhysicalPersoManagementWindow = new PhysicalPersoManagementWindow();
-            SetCenterPositionAndOpen(newPhysicalPersoManagementWindow);
-        }
-
-        private void OpenAddPhysicalPersonWindowMethod()
-        {
-            AddPhysicalPersonWindow newAddPhysicalPersonWindow = new AddPhysicalPersonWindow();
-            SetCenterPositionAndOpen(newAddPhysicalPersonWindow);
-        }
-
-        private void SetCenterPositionAndOpen(Window window)
-        {
-            window.Owner = Application.Current.MainWindow;
-            window.WindowStartupLocation = WindowStartupLocation.CenterOwner;
-            window.ShowDialog();
-        }
-
-
 
+            string result = _physicalPersonService.CreatePhysicalPerson(newPerson);
+            // Обновить список
+            AllPhysicalPeoples = _physicalPersonService.GetAllPhysicalPersons();
+        });
 
         public event PropertyChangedEventHandler PropertyChanged;
-
+        private void NotifyPropertyChanged(string propertyName) =>
-        private void NotifyPropertyChanged(String propertyName)
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
-        {
-            if (PropertyChanged != null)
-            {
-                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
-            }
-        }
     }
 }