create a ui with a button using gtk# in csharp

main.cs
public class MyWindow : Gtk.Window {
    // constructor
    public MyWindow() : base("My Gtk# App") {
        // set window size
        SetDefaultSize(320, 240);
        // create button
        var button = new Gtk.Button("Click me!");
        // add button to window
        Add(button);
        // show all children of window
        ShowAll();
        // connect button click event to event handler
        button.Clicked += OnButtonClicked;
    }
    
    // event handler for button click event
    private void OnButtonClicked(object sender, EventArgs args) {
        // handle button click event here
    }
}
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main.cs
static void Main(string[] args) {
    // initialize Gtk# library
    Gtk.Application.Init();
    
    // create new window
    var window = new MyWindow();
    
    // show window and start Gtk# main loop
    window.Show();
    Gtk.Application.Run();
}
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