add searchbar for UICollectionView

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(self.collectionView.frame), 44)];
    self.searchBar.autocorrectionType = UITextAutocorrectionTypeNo;
    self.searchBar.delegate = self;
    [self.collectionView addSubview:self.searchBar];
    [self.collectionView setContentOffset:CGPointMake(0, 44)];
}

- (void) viewWillAppear:(BOOL)animated{
    // to show search bar
    [self.collectionView setContentOffset:CGPointMake(0, 0)];
    // to hide search bar
    [self.collectionView setContentOffset:CGPointMake(0, 44)];
}

-(void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar {
    [searchBar setShowsCancelButton:YES animated:YES];
}

-(void)searchBarCancelButtonClicked:(UISearchBar *)searchBar {
    [searchBar setText:@""];
    [searchBar setShowsCancelButton:NO animated:YES];
    [searchBar resignFirstResponder];
}