how to create and display nodes dynamically in treeview

//This Sample is one way to bind data to a treenode.

class dataCls
{
public int Key { get; set; }
public object Data { get; set; }
}

class Sample
{
private void createTreeStructure()
{
// Your sql query using SqlDataAdapter or SqlDataReader.
// this example will use SqlDataReader

SqlConnection conn = new SqlConnection(connectionstring);
SqlCommand cmd = new SqlCommand(
"select cID, cName, cData from tblExample",
conn);

SqlDataReader dr = cmd.ExecuteReader();
while(dr.Read());
{
dataCls dataObj= new dataCls();
dataObj.Key = (int)dr[0];
dataObj.Data = dr[2];
TreeNone n = new TreeNode((string)dr[1]);
n.Tag = dataObj;
treeView1.Nodes.Add(n);
}
}
}