Hi
Can you try the below code
string cmn = dt.Rows[0]["company_name"].ToString();
if (dt.Rows.Count > 0)
{
TreeNode parentNode = new TreeNode();
parentNode.Text = cmn;
treeView1.Nodes.Add(parentNode);
for (int cn = 0; cn <= dt.Rows.Count - 1; cn++)
{
TreeNode child = new TreeNode();
child.Text = dt.Rows[cn]["fromdate"].ToString();
parentNode.Nodes.Add(child);
}
}