passing method name in threadstart but not getting any result...

SearchLink = new Thread(new ThreadStart(() =>getData("http://" + TextBox1.Text.Trim())));
            SearchLink.Start();
            SearchLink.Join();
            foreach (string value in myatt)
            {
                Label1.Text += value;
            }

private void getData(string Url) // you don't need to make any change on your getData method
    {
        HyperLink1.Text = string.Empty;
        HtmlWeb web = new HtmlWeb();
        HtmlDocument myNode = web.Load(Url);
 
        
        
        foreach (HtmlNode link in myNode.DocumentNode.SelectNodes("//a[@href]"))
        {
            HtmlAttribute att = link.Attributes["href"];
            myatt.Add(att.Value);
        }
        
    }