MainWindowViewModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Avalonia.Threading;
using DynamicData.Binding;
using July.Core.Plugin;
using July.Core.Services;
using ReactiveUI;

namespace July.ViewModels
{
    public class MainWindowViewModel : ViewModelBase
    {
        private CancellationToken _cancellationToken;
        private CancellationTokenSource _cancellationTokenSource;
        
        private List<IWallpaperInfo> _wallpapers = new();
        private string _searchString = "";

        public List<IWallpaperInfo> Wallpapers
        {
            get => _wallpapers;
            set => this.RaiseAndSetIfChanged(ref _wallpapers, value);
        }

        public string SearchString
        {
            get => _searchString;
            set
            {
                Dispatcher.UIThread.Post(LoadWallpapers);
                this.RaiseAndSetIfChanged(ref _searchString, value);
            }
        }

        public MainWindowViewModel()
        {
            _cancellationTokenSource = new CancellationTokenSource();
            _cancellationToken = _cancellationTokenSource.Token;

            Dispatcher.UIThread.Post(LoadWallpapers);
        }

        private async void LoadWallpapers()
        {
            _cancellationTokenSource.Cancel();
            
            _cancellationTokenSource = new CancellationTokenSource();
            _cancellationToken = _cancellationTokenSource.Token;
            
            Wallpapers = (await WallpaperPluginService.SelectedPlugin.Search(SearchString, 1, _cancellationToken)).ToList();
        }
    }
}