相关疑难解决方法(0)

我已经在navigatiom栏中实现了一个带有搜索栏的UISearchController,我想在加载视图时使搜索栏处于活动状态.当我说活动时,我的意思是键盘出现,用户可以在不点击搜索栏的情况下输入他/她的搜索.

我使用以下代码初始化了UISearchController:

- (void)viewDidLoad
{
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    [self.searchController setSearchResultsUpdater:self];
    [self.searchController setDimsBackgroundDuringPresentation:NO];
    [self.searchController setHidesNavigationBarDuringPresentation:NO];
    [self.navigationItem setTitleView:self.searchController.searchBar];

    [self setDefinesPresentationContext:YES];

    [self.searchController.searchBar setDelegate:self];
    [self.searchController.searchBar setShowsCancelButton:YES];
    [self.searchController.searchBar setPlaceholder:@"City or Airfield"];

    [self.searchController.searchBar sizeToFit];
}

我试图让我的搜索控制器处于活动状态,通话[self.searchController.searchBar becomeFirstResponder]并直接呼叫,searchBarSearchButtonClicked但没有任何作用.