Question

My DataBase Table Structure is like this :

ID(Primary Key ) , Title (Nvarchar) , ParentID (this is the ID of current table)

and the ‘ParentID’ of first node (root) is valued = -1
i loaded this data in Memory.(for example in a list of class)
how can i add the items with a loop or something else to TreeView ?

Answer 1

I did wrote this code :

  private void Heading_Load(object sender, System.EventArgs e)
{
    InsertNodes(null, 0);
}
private void InsertNodes(TreeNode n, int hdrID)
{
    System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection("Data Source=.\\sqlexpress;Initial Catalog=Acounting;Integrated Security=True;Pooling=False");
    con.Open();
    SqlCommand cmd = new SqlCommand("SELECT hdrid,title FROM [Heading] WHERE ParentID=" + hdrID, con);
    SqlDataReader rdr = cmd.ExecuteReader();
    while (rdr.Read()) {
        TreeNode t = new TreeNode(rdr("title").ToString());
        InsertNodes(t, Convert.ToInt16(rdr("hdrID").ToString()));
        if (n == null) {
            trvHeader.Nodes.Add(t);
        } else {
            n.Nodes.Add(t);
        }
    }
    rdr.Close();
         }

how is it?