Vision/VisionAsist/ViewModels/MainWindowViewModel.cs

using System;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input; 
using VisionAsist.Models;
namespace VisionAsist.ViewModels;

public partial class MainWindowViewModel : ViewModelBase
{
    [ObservableProperty]
    private bool isListening;
    [ObservableProperty]
    private string recognizedtext; 
    private Action<string>? _coreHandler;

    partial void OnIsListeningChanged(bool value)
    {
        if (value)
        {
            Core.StartListing();

            // Сохраняем ссылку на обработчик
            _coreHandler = word =>
            {
                
                Avalonia.Threading.Dispatcher.UIThread.Post(() =>
                {
                    Recognizedtext = Core.TextAsist;
                });
            };

            Core.triger.OnRecognized += _coreHandler;
        }
        else
        {
            Core.StopListing();

            // Правильная отписка
            if (_coreHandler != null)
            {
                Core.triger.OnRecognized -= _coreHandler;
                _coreHandler = null;
            }
        }
    }
}