procedure TCollectionEditor.AddClick(Sender: TObject);
var
  Item: TListItem;
  PrevCount: Integer;
begin
  SelectNone(False);
  Collection.BeginUpdate;
  try
    PrevCount := Collection.Count   1;
    Collection.Add;
    { Take into account collections that free items }
    if PrevCount <> Collection.Count then
      UpdateListBox
    else
      ListView1.Selected := ListView1.Items.Add;
  finally
    Collection.EndUpdate;
  end;
  SetSelection;
  if csAncestor in Component.ComponentState then
  begin
    if FAddedItemIDList = nil then
      FAddedItemIDList := TList.Create;
    FAddedItemIDList.Add(Pointer(Collection.Items[Collection.Count - 1].ID));
  end;
  Designer.Modified;//修改了屬性後，要通知屬性編輯器
  { Focus last added item }
  Item := ListView1.Items[ListView1.Items.Count-1];
  Item.Focused := True;
  Item.MakeVisible(False);
end;