How to Add Node Root In a Tree Using Asp.net Dynamically

Question

I want to bind a DataTable to a TreeView. I have written code .Its is currently working, which means it displays all the DataTable data, but there is no Node root.

List<DocumentData> lstData = GetSPDocuments(); gvDocuments.DataSource = lstData; gvDocuments.DataBind(); DataTable dt = ConvertToDataTable(lstData); TreeNode node1 = new TreeNode("Root"); foreach (DataRow r in dt.Rows) { int nodeLvl = int.Parse(r["ID"].ToString()); string nodeParent = "Folders"; string nodeName = r["Title"].ToString(); TreeNode tNode = new TreeNode(nodeName); ht.Add(nodeLvl.ToString() + nodeName, tNode); if (tvDocs.Nodes.Count == 0) tvDocs.Nodes.Add(tNode); else { nodeLvl--; tvDocs.Nodes.Add(tNode); } } 

How to add static Node root here ??? Please, help!

Answer 1

Try it, maybe this can help you.

  protected void Page_Load(object sender, EventArgs e) { conStr = ConfigurationManager.ConnectionStrings["conString"].ConnectionString; conn = new OleDbConnection(conStr); BindTreeViewControl(); } private void BindTreeViewControl() { try { DataSet ds = GetDataSet("Select ProductId,ProductName,ParentId from ProductTable"); DataRow[] Rows = ds.Tables[0].Select("ParentId = 0"); for (int i = 0; i < Rows.Length; i++) { TreeNode root = new TreeNode(Rows[i]["ProductName"].ToString(), Rows[i]["ProductId"].ToString()); root.SelectAction = TreeNodeSelectAction.Expand; CreateNode(root, ds.Tables[0]); treeviwExample.Nodes.Add(root); } } catch (Exception Ex) { throw Ex; } } public void CreateNode(TreeNode node, DataTable Dt) { DataRow[] Rows = Dt.Select("ParentId =" + node.Value); if (Rows.Length == 0) { return; } for (int i = 0; i < Rows.Length; i++) { TreeNode Childnode = new TreeNode(Rows[i]["ProductName"].ToString(), Rows[i]["ProductId"].ToString()); Childnode.SelectAction = TreeNodeSelectAction.Expand; node.ChildNodes.Add(Childnode); CreateNode(Childnode, Dt); } } private DataSet GetDataSet(string Query) { DataSet Ds = new DataSet(); try { OleDbDataAdapter da = new OleDbDataAdapter(Query, conn); da.Fill(Ds); } catch (Exception dex) { } return Ds; } 

and database structure for this

Answer 2

 // Suppress repainting the TreeView until all the objects have been created. treeView1.BeginUpdate(); // Clear the TreeView each time the method is called. treeView1.Nodes.Clear(); // create root node TreeNode root = new TreeNode("Root"); // loop and add all child nodes to root node foreach (DataRow r in dt.Rows) { // create child node // add to root node root.Nodes.Add(child); } // add root node to tree view treeView1.Nodes.Add(root); // Begin repainting the TreeView. treeView1.EndUpdate(); 

Answer 3

Have you ever received an answer? You were almost there.

What is the name of your TreeView control? Since you never said, I use treeView1 and modified your code to include this below:

 private TreeView treeView1; private void TreeView_DataBind() { treeView1.Nodes.Clear(); List<DocumentData> lstData = GetSPDocuments(); gvDocuments.DataSource = lstData; gvDocuments.DataBind(); DataTable dt = ConvertToDataTable(lstData); TreeNode node1 = new TreeNode("Root"); treeView1.Nodes.Add(node1); // this is the step you missed foreach (DataRow r in dt.Rows) { int nodeLvl = int.Parse(r["ID"].ToString()); string nodeParent = "Folders"; string nodeName = r["Title"].ToString(); TreeNode tNode = new TreeNode(nodeName); ht.Add(nodeLvl.ToString() + nodeName, tNode); if (tvDocs.Nodes.Count == 0) tvDocs.Nodes.Add(tNode); else { nodeLvl--; tvDocs.Nodes.Add(tNode); } } node1.Expand(); } 

Easy peasy!