Delphi: checking selection in Tree View

Question

There is a Tree View with 2 levels of items. I need to add a text of all selected "sub" (level 1) items into a Memo.

for i := 0 to pred(TreeView1.Items.count) do 
if (TreeView1.Items.Item[i].Selected) and (TreeView1.Items.Item[i].Level=1)
   then 
       begin
            Memo1.Lines.Add(TreeView1.Items.Item[i].Text)
       end;

But how to add all the "sub" items at once without their checking (selected or not) if their parent (level 0) is selected? E.g. I select the 3 items with the level 0 and their children are added into the Memo.

Thanks for help!

Answer 1

Only get level 1 nodes which have a selected parent:

var
  Node: TTreeNode;
  Sub: TTreeNode;
begin
  Node := TreeView.Items.GetFirstNode;
  while Node <> nil do
  begin
    if Node.Selected then
    begin
      Sub := Node.GetFirstChild;
      while Sub <> nil do
      begin
        Memo1.Lines.Add(Sub.Text);
        Sub := Sub.GetNextSibling;
      end;
    end;
    Node := Node.GetNextSibling;
  end;
end;

Update due to comment:

Get level 1 nodes which have a selected parent, or are selected themselves:

var
  I: Integer;
begin
  for I := 0 to TreeView.Items.Count - 1 do
    with TreeView.Items[I] do
      if (Level = 1) and (Selected or Parent.Selected) then
        Memo1.Lines.Add(Text);
end;

Answer 2

It seems to me that you are looking for all selected nodes which have a parent node. The easiest way to do that is as follows:

procedure EnumerateSelectedNonTopLevelItems(TreeView: TTreeView; List: TStrings);
var
  Node: TTreeNode;
begin
  for Node in TreeView.Items do
    if Node.Selected and Assigned(Node.Parent) then
      List.Add(Node.Text);
end;

This routine will give you nodes at levels 2, 3, 4 etc. Since you only have level 0 and level 1 this is fine. If you really did need the nodes that are direct descendants of top-level nodes then you can modify the test like this:

if Node.Selected and Assigned(Node.Parent) and not Assigned(Node.Parent.Parent) then