Програми для обліку

using Gtk;

class Program 
{
    static void Main()
    {        
        var app = Application.New("ua.org.accounting.test", Gio.ApplicationFlags.FlagsNone);

        app.OnActivate += (sender, args) =>
        {
            FirstWindow firstWindow = new(app);
            firstWindow.Show();
        };

        app.RunWithSynchronizationContext(null);
    }
}

using Gtk;
using static Gtk.Orientation;

class FirstWindow : Window
{
    public FirstWindow(Application app) : base()
    {
        Application = app;
        Title = "Window";

        SetDefaultSize(500, 300);

        Box vBox = Box.New(Vertical, 0);
        vBox.MarginTop = vBox.MarginBottom = vBox.MarginStart = vBox.MarginEnd = 10;
        Child = vBox;

        Button button = Button.NewWithLabel("Button");
        button.OnClicked += (sender, arrg) => Console.WriteLine(1);

        Button button2 = Button.NewFromIconName("application-exit");
        button2.OnClicked += (sender, arrg) => Console.WriteLine(2);

        Box hBox = Box.New(Horizontal, 10);
        hBox.Append(button);
        hBox.Append(button2);

        vBox.Append(hBox);
    }
}