Program.cs

using Gtk;
using LibVLCSharp.Shared;
using System;

namespace LibVLCSharp.GTK.Sample
{
    public class Program
    {
        public static void Main()
        {
            Core.Initialize();

            // Initializes the GTK# app
            Application.Init();

            using var libvlc = new LibVLC();
            using var mediaPlayer = new MediaPlayer(libvlc);

            // Create the window in code. This could be done in glade as well, I guess...
            var myWin = new Window("LibVLCSharp.GTK.Sample");
            myWin.Resize(800, 450);

            // Creates the video view, and adds it to the window
            var videoView = new VideoView { MediaPlayer = mediaPlayer };
            myWin.Add(videoView);

            //Show Everything
            myWin.ShowAll();

            //Starts playing
            using var media = new Media(libvlc,
                new Uri("http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4"));

            mediaPlayer.Play(media);

            myWin.DeleteEvent += (sender, args) =>
            {
                mediaPlayer.Stop();
                videoView.Dispose();
                Application.Quit();
            };

            Application.Run();
        }
    }
}