MPrakt/ViewModels/HotelsViewModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using ReactiveUI;
using TourAgent.Models;

namespace TourAgent.ViewModels
{
	public class HotelsViewModel : ReactiveObject
	{
        UP_SmirnovContext DB = new UP_SmirnovContext();

        private List<Hotel>? _hotels;
        public List<Hotel>? Hotels { get => _hotels; set => this.RaiseAndSetIfChanged(ref _hotels, value); }
        private int countElements = 10;
        public int CountElements { get => countElements; set => this.RaiseAndSetIfChanged(ref countElements, value); }
        private int _page = 1;
        public int Page { get => _page; set => this.RaiseAndSetIfChanged(ref _page, value); }
        private bool _enableOrNotRight = true;
        public bool EnableOrNotRight { get => _enableOrNotRight; set => this.RaiseAndSetIfChanged(ref _enableOrNotRight, value); }
        private bool _enableOrNotLeft = false;
        public bool EnableOrNotLeft { get => _enableOrNotLeft; set => this.RaiseAndSetIfChanged(ref _enableOrNotLeft, value); }
        int flagElementCount = 0;

        public HotelsViewModel() 
        { 
            Hotels = DB.Hotels.ToList();
            Hotels = Hotels.Take(CountElements).ToList();
            
        }

        public void NextPage()
        {
            Page++;
            Hotels = DB.Hotels.ToList();
            Hotels = Hotels.Skip((Page - 1) * CountElements).ToList();
            flagElementCount = Hotels.Count();
            Hotels = Hotels.Take(CountElements).ToList();
            EnableOrNotLeft = true;
            if (flagElementCount <= CountElements)
            {
                EnableOrNotRight = false;
            }
            else
            {
                EnableOrNotRight = true;
            }
        }

        public void PrevPage()
        {
            Page--;
            Hotels = DB.Hotels.ToList();
            Hotels = Hotels.Skip((Page-1)*CountElements).ToList();
            Hotels = Hotels.Take(CountElements).ToList();
            EnableOrNotRight = true;
            if (Page == 1)
            {
                EnableOrNotLeft = false;
            }
            else
            {
                EnableOrNotLeft = true;
            }
        }

        public void ToFirstPage()
        {
            Page = 1;
            Hotels = DB.Hotels.ToList();
            Hotels = Hotels.Take(CountElements).ToList();
            EnableOrNotLeft = false;
            EnableOrNotRight = true;
        }

        public void ToLastPage()
        {
            Hotels = DB.Hotels.ToList();
            Page = Hotels.Count / CountElements + 1;
            Hotels = Hotels.Skip(Page * CountElements).ToList();
            Hotels = Hotels.Take(CountElements).ToList();
            EnableOrNotRight = false;
            EnableOrNotLeft = true;
        }
    }
}