Topmost

public delegate void TopMostOrderDelegate();

public Program() {
    new Thread(() =>
    {
        while (true)
        {
            try
            {
                while (true)
                {
                    this.Invoke(new TopMostOrderDelegate(() => {
                        this.TopMost = true;
                    }));
                    Thread.Sleep(1);
                }
            } catch (Exception ex) { }
        }
    }).Start();
}