AvaloniaProject/AvaloniaApplication4/ViewModels/MainWindowViewModel.cs

using AvaloniaApplication4.AdditionalModels;
using AvaloniaApplication4.Models;
using AvaloniaApplication4.Views;
using Microsoft.EntityFrameworkCore;
using ReactiveUI;
using System.Collections.Generic;
using System.Linq;

namespace AvaloniaApplication4.ViewModels
{
    public class MainWindowViewModel : ViewModelBase
    {
        private string? message = "";
        public string? Login { get; set; }
        public string? Password { get; set; }
        public string? Message
        {
            get { return message; }
            set
            {
                if (message == value)
                    return;

                message = value;
                OnPropertyChanged("Message");
            }
        }
        GlobalsData globalsData = new();
        public GlobalsData GlobalsData { get => globalsData; set => globalsData = value; }

        public MainWindowViewModel()
        {
            globalsData = new GlobalsData();
            //GlobalsData.GlobalUserControl = new StartPage(user);
        }

        public void Next()
        {
            try
            {
                UsersLogin? currentUser = dataBase.UsersLogins.FirstOrDefault(x => x.Password == Password && x.UserEmail == Login);
                User? user;
                if (currentUser == null) Message = "Неверный логин или пароль";
                else
                {
                    Message = "";
                    user = dataBase.Users.FirstOrDefault(x => x.IdUser == currentUser.IdUser);
                    MainUserControl = new MainPage(user);
                }
            }
            catch { }
        }
    }
}