UISearchController 与 updateSearchResultsForSearchController

Question

我找到了如何实现 searchBar，但我不知道在 updateSearchResultsForSearchController 方法中要做什么。我所有的数据都是从 CoreData 中获取的。在这里我把我的代码。如果有人遇到类似问题，请告诉我该怎么做。

@interface PlumbListTableViewController ()<NSFetchedResultsControllerDelegate, UIPageViewControllerDelegate, UISearchBarDelegate, UISearchResultsUpdating, UISearchControllerDelegate>

@property (nonatomic, strong) NSFetchedResultsController *fetchedResultsController;
@property (nonatomic, strong) NSManagedObjectContext *managedObjectContext;
@property (nonatomic, strong) NSArray *array;
@property (nonatomic, strong) NSNumber *number;
@property (nonatomic) int sum;
@property (nonatomic, strong) PickerViewController *picker;
@property (nonatomic, strong) UISearchController *searchController;
@property (nonatomic, strong) NSMutableArray *fileteredTableData;
@property (nonatomic, strong) NSArray *products;
@property (nonatomic, strong) NSArray *recipies;
@property (nonatomic, strong) NSArray *searchResults;

@end

@implementation PlumbListTableViewController
-(void)viewDidLoad {
    [super viewDidLoad];

    //All data from CoreData
    self.products = [Product allProducts];
    self.searchResults = [NSMutableArray arrayWithCapacity:[self.products count]];

    [self.fetchedResultsController performFetch:nil];
    CoreDataStack *coreDataStack = [CoreDataStack defaultStack];
    NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"AddEntry"];
    fetchRequest.resultType = NSDictionaryResultType;
    self.recipies = [coreDataStack.managedObjectContext executeFetchRequest:fetchRequest error:nil];

}

-(void) viewWillAppear:(BOOL)animated {
    [super viewWillAppear:YES];
    [self initializeSearchController];
     self.tabBarController.tabBar.hidden = NO;
    [self showTotalSum];
    [self.tableView reloadData];
  }


-(void)initializeSearchController {
    //instantiate a search results controller for presenting the search/filter results (will be presented on top of the parent table view)
    UITableViewController *searchResultsController = [[UITableViewController alloc] initWithStyle:UITableViewStylePlain];

    searchResultsController.tableView.dataSource = self;

    searchResultsController.tableView.delegate = self;

    //instantiate a UISearchController - passing in the search results controller table
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:searchResultsController];

    //this view controller can be covered by theUISearchController's view (i.e. search/filter table)
    self.definesPresentationContext = YES;


    //define the frame for the UISearchController's search bar and tint
    self.searchController.searchBar.frame = CGRectMake(self.searchController.searchBar.frame.origin.x, self.searchController.searchBar.frame.origin.y, self.searchController.searchBar.frame.size.width, 44.0);

    self.searchController.searchBar.tintColor = [UIColor whiteColor];

    //add the UISearchController's search bar to the header of this table
    self.tableView.tableHeaderView = self.searchController.searchBar;


    //this ViewController will be responsible for implementing UISearchResultsDialog protocol method(s) - so handling what happens when user types into the search bar
    self.searchController.searchResultsUpdater = self;


    //this ViewController will be responsisble for implementing UISearchBarDelegate protocol methods(s)
    self.searchController.searchBar.delegate = self;
}

-(void)updateSearchResultsForSearchController:(UISearchController *)searchController {
 }

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"edit"]) {
        UITableViewCell *cell = sender;
        NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
        UINavigationController *navigationController = segue.destinationViewController;
        PlumbAddViewController *entryViewController = (PlumbAddViewController *)navigationController.topViewController;
        entryViewController.entry = [self.fetchedResultsController objectAtIndexPath:indexPath];

    }
}


-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return self.fetchedResultsController.sections.count;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.

        id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];
        return [sectionInfo numberOfObjects];
}

(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";
    ConfigureCellPlumb *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];


    AddEntry *entry = [self.fetchedResultsController objectAtIndexPath:indexPath];
    [cell configureCellforTable:entry];

    return cell;

}

-(NSFetchRequest *)entryListFetchRequest {
    NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"AddEntry"];

    fetchRequest.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"date" ascending:NO]];

    return fetchRequest;
}

-(NSFetchedResultsController *)fetchedResultsController {
    if (_fetchedResultsController != nil) {
        return _fetchedResultsController;
    }

    CoreDataStack *coreDataStack = [CoreDataStack defaultStack];
    NSFetchRequest *fetchRequest = [self entryListFetchRequest];

    _fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:coreDataStack.managedObjectContext sectionNameKeyPath:@"sectionName" cacheName:nil];
    _fetchedResultsController.delegate = self;

    return _fetchedResultsController;}

Answer 1

根据文档，updateSearchResultsForSearchController: 是 "called when the search bar's text or scope has changed or when the search bar becomes first responder."

因此，您希望在此方法中更新 table 以显示正确的搜索结果。这是我的样子（你的看起来会有所不同，但想法是一样的）：

- (void)updateSearchResultsForSearchController:(UISearchController *)searchController
{
    //make sure model has only results that correspond to the search
    [self updateFilteredContentWithSearchText:[self.searchController.searchBar text]];
    //update the table now that the model has been updated
    [self.specialtySearchResultsTVC.tableView reloadData];
}

//helper method
- (void)updateFilteredContentWithSearchText:(NSString*)searchText
{
    [self.specialtySearchResultsTVC.filteredSpecialties removeAllObjects];
    for (Specialty *specialty in self.specialties)
    {
        NSRange nameRange = [specialty.name rangeOfString:searchText options:NSCaseInsensitiveSearch];
        if (nameRange.location != NSNotFound)
        {
            [self.specialtySearchResultsTVC.filteredSpecialties addObject:specialty];
        }
    }
}

UISearchController 与 updateSearchResultsForSearchController

UISearchController with updateSearchResultsForSearchController

searchbar

uisearchcontroller