delphi 删除或清空一个目录(包含多级)

//use ShellApi;
function DelDirectory(const Source: string): boolean;
var
   fo: TSHFILEOPSTRUCT;
begin
   FillChar(fo, SizeOf(fo), 0);
   with fo do
   begin
      Wnd := 0;
      wFunc := FO_DELETE;
      pFrom := PChar(Source + #0);
      pTo := #0#0;
      fFlags := FOF_NOCONFIRMATION + FOF_SILENT;
   end;
   Result := (SHFileOperation(fo) = 0);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
   if DelDirectory('c:/1') then
   begin
      ForceDirectories('c:/1');
      ShowMessage('Success. ');
   end;
end;