FeedbackWindowsFormView.cs

public partial class FeedbackView : Form, IViewFor<FeedbackViewModel>
{
    public FeedbackView()
    {
        InitializeComponent();
        ViewModel = new FeedbackViewModel(new WinFormsSender(), new Clock());
        this.WhenActivated(subscriptions =>
        {
            this.Bind(ViewModel, x => x.Title, x => x.TitleTextBox.Text)
                .DisposeWith(subscriptions);
            this.OneWayBind(ViewModel, x => x.TitleLengthMax, x => x.TitleTextBox.MaxLength)
                .DisposeWith(subscriptions);
            
            this.WhenAnyValue(x => x.ViewModel.TitleLength, x => x.ViewModel.TitleLengthMax)
                .Select(values => $"{values.Item1} letters used from {values.Item2}")
                .BindTo(this, x => x.TitleLengthLabel.Text)
                .DisposeWith(subscriptions);

            this.BindCommand(ViewModel, x => x.Submit, x => x.SubmitButton)
                .DisposeWith(subscriptions);
            
            // Several lines of code are deliberately omitted for brevity, browse full project 
            // sources at: https://github.com/worldbeater/ReactiveMvvm
        });
    }

    public FeedbackViewModel ViewModel { get; set; }

    object IViewFor.ViewModel
    {
        get => ViewModel;
        set => ViewModel = (FeedbackViewModel)value;
    }
}