objective c - iOS Fix search bar on top of the UITableViewController?

Question

I'm adding search bar on table header and floating it in scrollViewDidScroll method, but when i scroll without click on search bar(i.e. i go to the view and do scroll) then search bar doesn't stay on top but it scroll up with table however once i click on search bar and click cancel button on search bar and then if i scroll the table, search bar stays on top.here is my code-

-(void)viewDidLoad {
    [super viewDidLoad];

    UISearchBar *searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
    searchBar.delegate = self;

    searchDisplayController = [[UISearchDisplayController alloc] initWithSearchBar:searchBar contentsController:self];
    searchDisplayController.delegate = self;
    searchDisplayController.searchResultsDataSource = self;
    searchDisplayController.searchResultsDelegate = self;

    UIView *tableHeaderView = [[UIView alloc] initWithFrame:searchDisplayController.searchBar.frame];
    [tableHeaderView addSubview:searchDisplayController.searchBar];
    [tableView setTableHeaderView:tableHeaderView];

    isSearching = NO;
}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView {

    UISearchBar *searchBar = searchDisplayController.searchBar;
    CGRect searchBarFrame = searchBar.frame;

    if (isSearching) {
        searchBarFrame.origin.y = 0;
    } else {
        searchBarFrame.origin.y = MAX(0, scrollView.contentOffset.y + scrollView.contentInset.top);
    }

    searchDisplayController.searchBar.frame = searchBarFrame;
}

- (void)searchDisplayControllerWillBeginSearch:(UISearchDisplayController *)controller {
    isSearching = YES;
}

-(void)searchDisplayControllerWillEndSearch:(UISearchDisplayController *)controller {
    isSearching = NO;
}

Note that I'm using UITableViewController sub class and don't want to change it to UIViewController. Any help would be appreciated.

Edit: I also using section header in this UITableViewController, in other UITableViewController there is no section header and this code working fine.Is this a problem with section header and table header together?

Answer 1

The reason why your searchbar is scrolling with the table contents is that you have put it directly IN the table, thus making it a child header section of the table. and that section ALWAYS scrolls…

Here is how this this can be achieved. And it is actually quite simple. (The following example relies on Storyboard, but the mechanism is the same whatever you are using) :

1) Use a UIVIewController and NOT a UITableViewController

2) Add a UITableView as the child of the parent UIView

3) Add a UISearchBarController also as a child view of the UIView, NOT as a child of the UITableView (UITableView and UISearchController are siblings)

you should have the following layout :

EDIT : The important thing to remember is to put the UISearchBarController ABOVE the sibling UITableView. Otherwise you may see the UITableView overlap the UISearchBarController when the latter is focused.

EDIT 2 : BTW, if you are using AutoLayout, remember to set the TOP constraint of the tableView relative to the SearchBar…

Run it and admire the result.

Hope this helps.