ios - 使 UISearchController 搜索栏自动激活

Question

我已经在导航栏中实现了一个带有搜索栏的 UISearchController，我希望在加载 View 时激活搜索栏。当我说事件时，我的意思是键盘出现并且用户可以在不点击搜索栏的情况下键入他/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];
}

我尝试激活我的搜索 Controller ，调用 [self.searchController.searchBar becomeFirstResponder] 并直接调用 searchBarSearchButtonClicked 但没有任何效果。

Answer 1

试着打电话

[self.searchController setActive:YES]

之前

[self.searchController.searchBar becomeFirstResponder]

如果上述方法不起作用，请尝试以下操作:

- (void)viewDidLoad {
    [super viewDidLoad];
    ...
    [self initializeSearchController];
    ....
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [self.searchController setActive:YES];
    [self.searchController.searchBar becomeFirstResponder];
}

- (void)initializeSearchController {
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    self.searchController.searchResultsUpdater = self;
    self.searchController.dimsBackgroundDuringPresentation = NO;
    self.searchController.delegate = self;
    self.searchController.searchBar.delegate = self;
    [self.searchController.searchBar sizeToFit];

    [self.tableView setTableHeaderView:self.searchController.searchBar];
    self.definesPresentationContext = YES;
}