public static ToDoListCategorySubWindow CreateCategorySubWindow(ToDoListCategoryListView listView,
                                                                 string name = "ToDoListCategorySubWindow")
 {
     //close 会自动destroy  所以都要重新new
     categorySubWindow = ToDoListCategorySubWindow.Open(listView, name);
     return(categorySubWindow);
 }
        protected override void Dispose()
        {
            if (categorySubWindow)
            {
                categorySubWindow.Close();
                categorySubWindow = null;
            }

            instance = null;
        }