navigationItem.searchController行为与ios12不同

Question

在iOS12中，navigationItem.searchController应该在按下时显示，在按下时隐藏。 ios13中的错误，它可以显示但不能隐藏，除非您的列表比屏幕长，以下是我的代码，在ios12中可以正常工作：

_searchController.searchResultsUpdater = self;
_searchController.obscuresBackgroundDuringPresentation = NO;
_searchController.searchBar.placeholder = SP_LOCSTR(@"Search");
_searchController.searchBar.tintColor = [UIColor whiteColor];
_searchController.dimsBackgroundDuringPresentation = NO;
_searchController.hidesNavigationBarDuringPresentation = YES;
_searchController.delegate = self;
self.navigationItem.searchController = _searchController;
self.navigationItem.hidesSearchBarWhenScrolling = YES;