private void TreeView1Config() { treeView1.Nodes[1].Nodes[0].Nodes.Clear(); ATINChamCongEntities context = new ATINChamCongEntities(); var phongBans = context.spGetAllPhongBan().ToList(); treeView1.Nodes[0].Tag = new PhongBan(); treeView1.Nodes[1].Tag = new PhongBan(); treeView1.Nodes[1].Nodes[0].Tag = new PhongBan(); foreach (var phong in phongBans) { TreeNode node = new TreeNode(phong.TenPhongBan); node.Tag = phong; treeView1.Nodes[1].Nodes[0].Nodes.Add(node); } treeView1.ExpandAll(); }