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How to stop TreeView repopulating the same node?

Hi,
I have a TreeView which has 5 level of child nodes, the thing is I've placed an AfterSelect event after clciking on the 4th level to generate my 5th level of child nodes.But the problem is when ever I click on the same 4th level the same thing will generate again @ the 5th level.

How can I stop it from duplicating the same nodes?
My code for the AfterSelect Event is something like this.

//Connected to database
// Populate 5th level in TreeView
foreach (DataRow dr in ordt.Rows)
{
TreeNode newNode = new TreeNode();
newNode.Text =  dr[4].ToString();
 e.Node.Nodes.Add(newNode);
}

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Dmitry G

I believe one possible way is to check if a child node with the same text exists or something like that.

May a 4th level node have more than one child? If not - check number of children. If 0 - add, if 1 - skip.

csharp_learner

ASKER

Unfortunately my 4th node does have more then 1 child.
Example:
-X01
-product
-hardware
- brand
-alpha
-alpha.101(read from new database)
-alpha.102(read from new database)
-beta

Dmitry G

OK, still it's not a problem.
May these children have same text?
What's the difference between them?
May be you need to set the Tag property (to some specific value) when creating new nodes and later check that no children with the samer tag?

Another possible trick - to add the node to some "handled" list. If in the list - skipp adding nodes; not in the list - add nodes and add to the list.

HarryNS

Hey... You still have the same problem.

Can you give me your code.... I will get you the answer...

csharp_learner

ASKER

Thanks for offering your help harry.
This is the AfterSelect event code.

private void treeview1_AfterSelect(object sender, TreeViewEventArgs e)
        {            localSQL = "SELECT KEYID,PRODUCT_NAME,PRODUCT_DESC,PKEYID,PRODUCT_TYPE FROM PRODUCT_PT WHERE PKEYID LIKE '" + treeScadaItems.SelectedNode.Name + "'";
            OracleCommand cmdOracle = new OracleCommand(localSQL, localConnection);
            cmdOracle.CommandType = CommandType.Text;
            OracleDataReader drOracle = cmdOracle.ExecuteReader(); 
            DataTable ordt = new DataTable();
            OracleDataAdapter orda = new OracleDataAdapter();
            orda.SelectCommand = cmdOracle;
            orda.Fill(ordt);
            drOracle.Close();
 
                    if (e.Node.Level == 4)
                    {
                        try
                        {
                            // Populate PRODUCT_PT level 5 in TreeView
                            foreach (DataRow dr in ordt.Rows)
                            {
                                string[] strlist = dr[1].ToString().Split('.');
                                TreeNode newNode = new TreeNode();
                                newNode.Text = strlist[5] + " ( " + dr[4].ToString() + " )";
                                e.Node.Nodes.Add(newNode);
                            }
                        }
                        catch (Exception newview)
                        {
                            MessageBox.Show(newview.ToString());
                        }
                    }

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HarryNS

This code works for me...

private void treeview1_AfterSelect(object sender, TreeViewEventArgs e)
        {
            if (e.Node.Level == 4)
            {
                localSQL = "SELECT KEYID,PRODUCT_NAME,PRODUCT_DESC,PKEYID,PRODUCT_TYPE FROM PRODUCT_PT WHERE PKEYID LIKE '" + treeScadaItems.SelectedNode.Name + "'";
                OracleCommand cmdOracle = new OracleCommand(localSQL, localConnection);
                cmdOracle.CommandType = CommandType.Text;
                OracleDataReader drOracle = cmdOracle.ExecuteReader();
                DataTable ordt = new DataTable();
                OracleDataAdapter orda = new OracleDataAdapter();
                orda.SelectCommand = cmdOracle;
                orda.Fill(ordt);
                drOracle.Close();
 
 
                TreeNode nodeCheck = null;
                TreeNode[] node = null;
                string strText = string.Empty;
                string[] strList = null;
 
                try
                {
                    // Populate PRODUCT_PT level 5 in TreeView
                    foreach (DataRow dr in ordt.Rows)
                    {
                        nodeCheck = new TreeNode();
                        nodeCheck.Name = dr[0].ToString();
                        strText = dr[2].ToString();
                        strList = strText.Split('.');
                        if (strList != null)
                        {
                            nodeCheck.Text = strList[strList.Length - 1];
                        }
                        else
                            nodeCheck.Text = strText;
                        if (dr[1] != DBNull.Value)
                        {
                            node = treeView1.Nodes.Find(dr[1].ToString(), true);
                            if (node != null && node.Length > 0)
                            {
                                node[0].Nodes.Add(nodeCheck);
                            }
                        }
                        else
                        {
                            e.Node.Nodes.Add(nodeCheck);
                        }
                    }
                }
                catch (Exception newview)
                {
                    MessageBox.Show(newview.ToString());
                }
            }
        }

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HarryNS

Please change Line No. 38 in my code
FROM: node = treeView1.Nodes.Find(dr[1].ToString(), true);
TO: node = e.Node.Nodes.Find(dr[1].ToString(), true);

csharp_learner

ASKER

The code ran but nothing was displayed out on the TreeView...

HarryNS

Will your Call to DB on Node 5 have sub items or not???

ASKER CERTIFIED SOLUTION

HarryNS

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