UISearchController searchBar在推送viewcontroller时不会消失

Question

我正在使用UIViewcontroller包含a 的UISearchController UITableView,我这样做viewDidLoad:

    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    self.searchController.delegate = self;
    self.searchController.searchResultsUpdater = self;
    self.searchController.searchBar.delegate = self;
    self.searchController.dimsBackgroundDuringPresentation = NO;
    self.searchController.hidesNavigationBarDuringPresentation = NO;
    self.definesPresentationContext = NO;

当我按下导航栏中的按钮时,我这样做:

    self.tableView.contentOffset = CGPointMake(0, 0 - self.tableView.contentInset.top);
    self.tableView.tableHeaderView = self.searchController.searchBar;
    [self.searchController.searchBar becomeFirstResponder];

一切正常,但是当我UIViewController在UITableView结果中从一行中推出一个UISearchBar停留在那里并显示另一个视图的内容时,当我推回视图并且当我回去看看结果时我怎么能解雇UITableView？

谢谢

编辑:

这是方法的代码didSelectRowAtIndexPath:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];
    DetailListController *detailList = [[DetailListController alloc] init];
    [self.navigationController pushViewController:detailList animated:YES];
}

Answer 1

把这段代码放在你的viewDidLoad:

self.definesPresentationContext = YES;

Answer 2

当你从DetailListController视图控制器返回时需要调用它(为了安全起见,封装在主线程中):

dispatch_async(dispatch_get_main_queue(), ^{
    self.searchController.active = NO;
});

您也可以在viewWillDisappear:当前的视图控制器中调用它.

Answer 3

尝试苹果建议的标准方法：

声明属性：

@interface APLMainTableViewController () <UISearchBarDelegate, UISearchControllerDelegate, UISearchResultsUpdating>

@property (nonatomic, strong) UISearchController *searchController;

// our secondary search results table view
@property (nonatomic, strong) APLResultsTableController *resultsTableController;

// for state restoration
@property BOOL searchControllerWasActive;
@property BOOL searchControllerSearchFieldWasFirstResponder;

@end



    - (void)viewDidLoad {
    [super viewDidLoad];

    _resultsTableController = [[APLResultsTableController alloc] init];
    _searchController = [[UISearchController alloc] initWithSearchResultsController:self.resultsTableController];
    self.searchController.searchResultsUpdater = self;
    [self.searchController.searchBar sizeToFit];
    self.tableView.tableHeaderView = self.searchController.searchBar;

    // we want to be the delegate for our filtered table so didSelectRowAtIndexPath is called for both tables
    self.resultsTableController.tableView.delegate = self;
    self.searchController.delegate = self;
    self.searchController.dimsBackgroundDuringPresentation = NO; // default is YES
    self.searchController.searchBar.delegate = self; // so we can monitor text changes + others

    // Search is now just presenting a view controller. As such, normal view controller
    // presentation semantics apply. Namely that presentation will walk up the view controller
    // hierarchy until it finds the root view controller or one that defines a presentation context.
    //
    self.definesPresentationContext = YES;  // know where you want UISearchController to be displayed
}

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    // restore the searchController's active state
    if (self.searchControllerWasActive) {
        self.searchController.active = self.searchControllerWasActive;
        _searchControllerWasActive = NO;

        if (self.searchControllerSearchFieldWasFirstResponder) {
            [self.searchController.searchBar becomeFirstResponder];
            _searchControllerSearchFieldWasFirstResponder = NO;
        }
    }
}


#pragma mark - UISearchBarDelegate

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar {
    [searchBar resignFirstResponder];
}


#pragma mark - UISearchControllerDelegate

// Called after the search controller's search bar has agreed to begin editing or when
// 'active' is set to YES.
// If you choose not to present the controller yourself or do not implement this method,
// a default presentation is performed on your behalf.
//
// Implement this method if the default presentation is not adequate for your purposes.
//
- (void)presentSearchController:(UISearchController *)searchController {

}

- (void)willPresentSearchController:(UISearchController *)searchController {
    // do something before the search controller is presented
}

- (void)didPresentSearchController:(UISearchController *)searchController {
    // do something after the search controller is presented
}

- (void)willDismissSearchController:(UISearchController *)searchController {
    // do something before the search controller is dismissed
}

- (void)didDismissSearchController:(UISearchController *)searchController {
    // do something after the search controller is dismissed
}

有趣的部分来了：当您从详细视图返回时，使用以下代码恢复状态

#pragma mark - UIStateRestoration

// we restore several items for state restoration:
//  1) Search controller's active state,
//  2) search text,
//  3) first responder

NSString *const ViewControllerTitleKey = @"ViewControllerTitleKey";
NSString *const SearchControllerIsActiveKey = @"SearchControllerIsActiveKey";
NSString *const SearchBarTextKey = @"SearchBarTextKey";
NSString *const SearchBarIsFirstResponderKey = @"SearchBarIsFirstResponderKey";

- (void)encodeRestorableStateWithCoder:(NSCoder *)coder {
    [super encodeRestorableStateWithCoder:coder];

    // encode the view state so it can be restored later

    // encode the title
    [coder encodeObject:self.title forKey:ViewControllerTitleKey];

    UISearchController *searchController = self.searchController;

    // encode the search controller's active state
    BOOL searchDisplayControllerIsActive = searchController.isActive;
    [coder encodeBool:searchDisplayControllerIsActive forKey:SearchControllerIsActiveKey];

    // encode the first responser status
    if (searchDisplayControllerIsActive) {
        [coder encodeBool:[searchController.searchBar isFirstResponder] forKey:SearchBarIsFirstResponderKey];
    }

    // encode the search bar text
    [coder encodeObject:searchController.searchBar.text forKey:SearchBarTextKey];
}

- (void)decodeRestorableStateWithCoder:(NSCoder *)coder {
    [super decodeRestorableStateWithCoder:coder];

    // restore the title
    self.title = [coder decodeObjectForKey:ViewControllerTitleKey];

    // restore the active state:
    // we can't make the searchController active here since it's not part of the view
    // hierarchy yet, instead we do it in viewWillAppear
    //
    _searchControllerWasActive = [coder decodeBoolForKey:SearchControllerIsActiveKey];

    // restore the first responder status:
    // we can't make the searchController first responder here since it's not part of the view
    // hierarchy yet, instead we do it in viewWillAppear
    //
    _searchControllerSearchFieldWasFirstResponder = [coder decodeBoolForKey:SearchBarIsFirstResponderKey];

    // restore the text in the search field
    self.searchController.searchBar.text = [coder decodeObjectForKey:SearchBarTextKey];
}

@end