VeloeAvaloniaKemonoPartyApplication/VeloeAvaloniaKemonoPartyApp/VeloeAvaloniaKemonoPartyApp/ViewModels/PostImageViewModel.cs

using Avalonia.Interactivity;
using Avalonia.Media.Imaging;
using Avalonia.Threading;
using HanumanInstitute.MvvmDialogs;
using ReactiveUI;
using System;
using System.Threading.Tasks;
using VeloeAvaloniaKemonoPartyApp.Models;

namespace VeloeAvaloniaKemonoPartyApp.ViewModels
{
    public class PostImageViewModel : ViewModelBase
    {
        private Attachment _attachment;
        private readonly IDialogService _dialogService;
        public PostImageViewModel(IDialogService dialogService,Attachment attachment)
        {
            _attachment = attachment;
            _dialogService = dialogService;
        }

        private Bitmap? _cover;

        public Bitmap? Cover
        {
            get => _cover;
            private set => this.RaiseAndSetIfChanged(ref _cover, value);
        }

        public async Task LoadAvatar()
        {
            await using (var imageStream = await _attachment.LoadCoverBitmapAsync())
            {
                if (imageStream is null) return;

                Cover = await Task.Run(() =>
                {
                    Bitmap? bitmap;
                    try
                    {
                        bitmap = new Bitmap(imageStream);
                        bitmap = bitmap.CreateScaledBitmap(new Avalonia.PixelSize(bitmap.PixelSize.Width / 2, bitmap.PixelSize.Height / 2));
                    }
                    catch (Exception ex)
                    {
                        bitmap = null;
                    }
                    return bitmap;
                });
            }
        }

        public async Task OnImageClick(object sender, RoutedEventArgs e)
        {
            var vm = new ImageZoomViewModel(_attachment);
            _dialogService.Show((_dialogService.DialogManager as HanumanInstitute.MvvmDialogs.Avalonia.DialogManager).NavigationManager.CurrentViewModel, vm);
        }

    }
}