Run your scrapy code within a button click event in the win form code withing a separate task similar to this
Task.Factory.StartNew(() =>
{
Forum forum = new Forum(txtUsername.Text, pass);
Subject s = forum.AnalyzeSubject(id, ct.Token);
foreach (var item in s.CategoryActivity.OrderByDescending(so=>so.Count))
{
this.txtRez.BeginInvoke(new Action(() =>
{
this.txtRez.Text += item.ToString() + "\r\n";
}));
}
});