UISearchBar textDidChange not firing

Question

I'm new to iOS programming, and I'm not sure why my textDidChange function is not firing. Searched online a bunch, but can't find out what's different between my code and everyone else's. Here's what my .h and .m files look like for this view controller:

CategoryTableViewController.h :

#import <UIKit/UIKit.h>
#import <Parse/Parse.h>

@interface CategoryTableViewController : UITableViewController


@property (weak, nonatomic) IBOutlet UIBarButtonItem *btnBack;
@property (weak, nonatomic) IBOutlet UISearchBar *txtSearchBar;

@property (strong,nonatomic) NSArray *allCategories;
@property (strong,nonatomic) NSMutableArray *filteredCategories;

//A stack containing the parent categories used to get to the current category.
@property (strong, nonatomic) NSMutableArray *parentCategories;

@end

Relevant code from CategoryTableViewController.m :

-(void)txtSearchBar:(UISearchBar*)txtSearchBar textDidChange: (NSString*)text
{

    //do something
}

I used Xcode's ctrl+click+drag to create the reference to the search bar in the header file. I put breakpoints and print statements at the start of the textDidChange code, but none of it ever gets called. Any ideas?

Answer 1

You need to set the delegate property of txtSearchBar to use the delegate methods. Make sure you add

    self.txtSearchBar.delegate = self; 

in ViewDidLoad()

and the delegate method

 - (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{

    //Do something

    }

Answer 2

If you're using a delegate method be sure to set the delegate property on the instance that needs to call the delegate so it knows there is a delegate and where to send actions.

if you're using Interface Builder and not delegate, you need to create an IBAction function, or you can use a UIControl's subclass addTarget() method to create a callback for a given event type.

Answer 3

Add

self.txtSearchBar.delegate = self 

in viewDidLoad().