How to populate a tree view based on a flat list with “levels”?

Question

I have a list of objects populated from a third-party project file. The way this file was designed is so each item is on a \"level\" of hierarchy. So the very first item is

Answer 1

Try something like this:

var
  Item: TMyItem;
  Node: TTreeNode;
  NodeLevel: Integer;
  X: Integer;
begin
  Node := nil;
  NodeLevel := 0;
  for X := 0 to MyList.Count-1 do
  begin
    Item := MyList[X];
    if (Node = nil) or (Item.Level <= 0) then
    begin
      Node := TreeView1.Items.AddObject(nil, Item.Text, Item);
      NodeLevel := 0;
    end
    else if Item.Level = NodeLevel then
    begin
      Node := TreeView1.Items.AddObject(Node, Item.Text, Item);
    end else
    begin
      while Item.Level <= NodeLevel do
      begin
        Node := Node.Parent;
        Dec(NodeLevel);
      end;
      Node := TreeView1.Items.AddChildObject(Node, Item.Text, Item);
      Inc(NodeLevel);
    end;
    // set Node properties as needed...
  end;
end;