public void OnNavigatedTo(NavigationContext navigationContext)
        {
            _journal = navigationContext.NavigationService.Journal;

            var item = navigationContext.Parameters["ToDoItem"] as ToDoItem;

            if (item != null)
            {
                SelectedItem = item;
                TempItem     = null;
                TempItem     = SelectedItem.DeepCopy();
                contentDirty = false;
            }
        }