private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { btnAddDestinatario.Enabled = treeView1.SelectedNode != null; btnRimuoviDuplicati.Enabled = treeView1.SelectedNode != null; if (treeView1.SelectedNode == null) { _elencoDestintari = new BindingList <Destinatario>(new List <Destinatario>()); dataGridView1.DataSource = _elencoDestintari; } else { var list = AppRepo.GetDestinatari((string)treeView1.SelectedNode.Tag).OrderBy(x => x.Address?.ToLower()).ToList(); _elencoDestintari = new BindingList <Destinatario>(list); dataGridView1.DataSource = _elencoDestintari; } }