avaloniax/AvaloniaHomeTry/ViewModels/MainWindowViewModel.cs

using Avalonia.Controls;
using AvaloniaHomeTry.Models;
using AvaloniaHomeTry.Views;
using ReactiveUI;
using System.Linq;

namespace AvaloniaHomeTry.ViewModels
{
    public class MainWindowViewModel : ViewModelBase
    {


        public int ID;
        private UserControl uc = new AuthPage();
        public UserControl UC { get => uc; set =>this.RaiseAndSetIfChanged(ref uc, value); }


        AuthPageViewModel contentDbVM = new AuthPageViewModel();
        public AuthPageViewModel ContentDbVM { get => contentDbVM; set => contentDbVM = value; }

        public static MainWindowViewModel Self;
        public MainWindowViewModel()
        {
            Self = this;
        }

        public void Registration() => MainWindowViewModel.Self.UC = new RegistrationPage(); 

        public void Enter()
        {
            UsersTable? currentUser = db.UsersTable.FirstOrDefault(x=>x.Login == ContentDbVM.Login && x.Password == ContentDbVM.Password);
            if (currentUser == null)
            {
                ContentDbVM.Message = "Нет такого пользователя";
            }
            else
            {
                ID = currentUser.Id;
                switch (currentUser.IdRole)
                {
                    case 1:
                        UC = new AdminPage();
                        break;
                    case 2:
                        UC = new UserPage(currentUser.Id);
                        break;
                }
            }
        }
    }
}