使用UISearchController和Objective-C搜索UITableView而不是UITableViewController

Question

Explanation: I cant find any tutorials telling me how to search a UITableView with the new UISearchController that is compatible for iOS 8 and uses Objective-C . I have an NSMutableArray defined called 'users' which has all the users from my Parse.com query and I have a small table view in my View Controller called 'usersTable' the methods for my usersTable are as follows:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"userCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    PFObject *tempObject = [users objectAtIndex:indexPath.row];

    cell.text= [tempObject objectForKey:@"username"];

    return cell;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    NSLog(@"users:%lu",[users count]);
    return [users count];
}

Body 1: All I want to do is filter out the data that the user typed in the search bar using UISearchController NSMutableArray called users and then display it onto 'usersTable.' It'd be very helpful if you guys could give an example to understand.

Conclusion: Could somebody please, please help me as I have no idea on how to go about this as there are no explanations for the UISearchController at this point in time with Objective-C. I'd appreciate any help.

Thanks for your help.

BTW: I don't want you guys to do this for me. I just want something I can understand. Maybe some instructions or an example if possible. There are some SO posts on this but they don't make any sense.

Answer 1

If you're just looking for some code and an explanation to go off of, I'd recommend looking at Apple's sample project here:

https://developer.apple.com/library/ios/samplecode/TableSearch_UISearchController/Introduction/Intro.html

The main things to note are that you can't do this from a storyboard. Instead, you will create a property of type UISearchController on the view controller where your search currently lives. Then, you'll create a new class that is either a subclass of UITableViewController or has a UITableView on it, and you will set that as the searchResultsController of the your SearchController property.

Another important thing to note is that unlike in the past with UISearchDisplayController , UISearchController is a whole different view controller that displays your search results on top of your main table view. (This is achieved by the definesPresentationContext variable in the code).

While Apple provides you everything you need in the link above, here is the most important part of the code with some comments:

- (void)viewDidLoad {
    [super viewDidLoad];
    // results table controller is the same as what your search display controller used to be
    _resultsTableController = [[APLResultsTableController alloc] init];
    _searchController = [[UISearchController alloc] initWithSearchResultsController:self.resultsTableController];
    // this says 'tell this view controller when search updates are available'
    self.searchController.searchResultsUpdater = self;
    // this places the search bar atop the table view since it's hard to do this via storyboard
    [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
}