Delphi, VirtualStringTree - classes (objects) instead of records

Question

I need to use a class instead of record for VirtualStringTree node.

Should I declare it standard (but in this case - tricky) way like that:

PNode = ^         


        

Answer 1

1. Setup datasize for holding object

   vstTree.NodeDataSize := SizeOf(TMyObject); 
   

2. Get the datasize holder and bind to your object

   vstTree.getNodeData(passed in interested node)^ := your object
   

   or

   vstTree.getNodeData(vstTree.AddChild(nil))^ := TMyObject.Create;
   

   or
   use vstTree.InsertNode method

3. To free the binding object hookup the OnFreeNode event

   vstTree.OnFreeNode := FreeNodeMethod;
   

   with

   procedure TFoo.FreeNodeMethod(Sender: TBaseVirtualTree; Node: PVirtualNode);
   var
     P: ^TMyObject;
   begin
     P := Sender.getNodeData(Node);
     if P <> nil then
     begin
         P^.Free;
         P^ := nil; //for your safety or you can omit this line
     end;
   end;