demka/demofinish/MainWindow.axaml.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.IO;
using System.Linq;
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Media.Imaging;
using demofinish.Models;

namespace demofinish
{
    public partial class MainWindow : Window
    {
        private ObservableCollection<Agent> agents = new ObservableCollection<Agent>();
        public List<AgentPresenter> agentsList = new List<AgentPresenter>();
        private const int pageSize = 10;
        private int currentPage = 1;
        private int pageCount = 0;

        public MainWindow()
        {
            InitializeComponent();
            LoadAgents();
            ComboboxPriority();
            PriorityCombobox.SelectionChanged += PriorutyCombobox_SelectionChanged;
        }


        


        public class AgentPresenter : Agent
        {
            Bitmap? LogoImage
            {
                get
                {
                    try
                    {
                        var absolutepass = Path.Combine(AppContext.BaseDirectory, Logo);
                        return new Bitmap(absolutepass);

                    }
                    catch
                    {
                        return null;
                    }
                }
            }
        }

        private void ComboboxPriority()
        {
            using var context = new User1Context();
            
            var priorities = context.Agents
                .Select(x => x.Priority)
                .Distinct()
                .OrderBy(x => x)
                .ToList()  
                .Cast<object>() 
                .ToList();
    
            priorities.Insert(0, "Все типы");
    
            PriorityCombobox.ItemsSource = priorities;
            PriorityCombobox.SelectedIndex = 0;
        }

        private void PriorutyCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            
            currentPage = 1;
            ShowCurrentPage();
            if (PriorityCombobox.SelectedItem == null) 
                return;

            if (PriorityCombobox.SelectedItem is string && (string)PriorityCombobox.SelectedItem == "Все типы")
            {
                AgentListBox.ItemsSource = agents;
            }
            else if (PriorityCombobox.SelectedItem is int priority)
            {
                AgentListBox.ItemsSource = agents.Where(x => x.Priority == priority).ToList();
            }
        }



    private void LoadAgents()
        {
            using var context = new User1Context();


            agentsList = context.Agents.Select(agentPresenter => new AgentPresenter
            {
                Id = agentPresenter.Id,
                Title = agentPresenter.Title,
                Agenttypeid = agentPresenter.Agenttypeid,
                Address = agentPresenter.Address,
                Inn = agentPresenter.Inn,
                Kpp = agentPresenter.Kpp,
                Directorname = agentPresenter.Directorname,
                Phone = agentPresenter.Phone,
                Email = agentPresenter.Email,
                Logo = agentPresenter.Logo,
                Priority = agentPresenter.Priority,
            }).ToList();
            
            
            
            foreach (var agent in agentsList)
            {
                agents.Add(agent);
            }
            
            AgentListBox.ItemsSource = agents;
            
            pageCount = (int)Math.Ceiling(agentsList.Count / (double) pageSize);
            ShowCurrentPage();
        }

        private void ShowCurrentPage()
        {
            agents.Clear();

            var pageAgents = agentsList.Skip((currentPage - 1) * pageSize).Take(pageSize);
            foreach (var e in pageAgents)
            {
                agents.Add(e);
            }
        }

        private void NextPage()
        {
            if (currentPage < pageCount)
            {
                currentPage++;
                ShowCurrentPage();
            }
        }

        private void PrevPage()
        {
            if (currentPage > 1)
            {
                currentPage--;
                ShowCurrentPage();
            }
        }
        
        

        private void PrevPage_Click(object sender, RoutedEventArgs e) => PrevPage();

        private void NextPage_Click(object sender, RoutedEventArgs e) => NextPage();
    }
}