delphi – 在树视图节点内存储接口指针

我也试图使用手动引用计数,正如我在another question中看到的那样.然而,它仍然是零,现在给内存泄漏.

//Clears tree view and adds drive letters
procedure TfrmMain.cmdRefreshBrowseClick(Sender: TObject);
var
  Arr,O: ISuperObject;
  X: Integer;
  N,C: TTreeNode;
begin
  //First clear all items and release their interface refs
  for N in tvBrowse.Items do begin
    O:= ISuperObject(N.Data);
    O._Release;
  end;
  tvBrowse.Items.Clear;
  Arr:= ListDirectory(''); //Returns ISuperObject array listing drives
  for X := 0 to Arr.AsArray.Length-1 do begin
    O:= Arr.AsArray.O[X];
    N:= tvBrowse.Items.Add(nil,O.S['drive']+': ['+O.S['type']+']'); //Add root node
    N.Data:= Pointer(O); // Assign interface pointer to node data
    O._AddRef; //Manually increment interface reference count
    C:= tvBrowse.Items.AddChild(N,''); //Add a fake child node
  end;
end;

procedure TfrmMain.tvBrowseExpanding(Sender: TObject; Node: TTreeNode;
  var AllowExpansion: Boolean);
var
  N,C: TTreeNode;
  P,A,O: ISuperObject;
  X: Integer;
begin
  //Check first node if it's a fake node
  N:= Node.getFirstChild;
  if N.Text = '' then begin //if first node is a fake node...
    P:= ISuperObject(Node.Data); // <-- P always comes out nil here???
    N.Delete; //Delete first "fake" node
    //Get child files/folders
    if Node.Parent = nil then //If root (drive) node...
      A:= ListDirectory(P.S['drive']+':') //Returns ISuperObject array listing files/folders
    else
      A:= ListDirectory(P.S['name']); //Returns ISuperObject array listing files/folders
    for X := 0 to A.AsArray.Length-1 do begin
      O:= A.AsArray.O[X];
      C:= tvBrowse.Items.AddChild(N,O.S['name']); //Add child node
      C.Data:= Pointer(O); //Assign interface pointer to node data
      O._AddRef; //Manually increment reference count
    end;
  end;
end;

这样做的适当方法是什么？