Я добавил пользовательский контроллер меню при долгом нажатии на UICollectionViewCell

    [self becomeFirstResponder];
    UIMenuItem *menuItem = [[UIMenuItem alloc] initWithTitle:@"Custom Action"
                                                      action:@selector(customAction:)];
    [[UIMenuController sharedMenuController] setMenuItems:[NSArray arrayWithObject:menuItem]];
    [[UIMenuController sharedMenuController] setTargetRect: self.frame inView:self.superview];
    [[UIMenuController sharedMenuController] setMenuVisible:YES animated: YES];

canBecomeFirstResponder также вызывается

- (BOOL)canBecomeFirstResponder {
    // NOTE: This menu item will not show if this is not YES!
    return YES;
}

// Этот метод не вызывается

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    NSLog(@"canPerformAction");
    // The selector(s) should match your UIMenuItem selector
    if (action == @selector(customAction:)) {
        return YES;
    }
    return NO;
}

Я также реализовал эти методы

- (BOOL)collectionView:(UICollectionView *)collectionView
      canPerformAction:(SEL)action
    forItemAtIndexPath:(NSIndexPath *)indexPath
            withSender:(id)sender {


    if([NSStringFromSelector(action) isEqualToString:@"customAction:"]){
        NSLog(@"indexpath : %@",indexPath);
        UIAlertView *alertview = [[UIAlertView alloc] initWithTitle:@"warning.." message:@"Do you really want to delete this photo?" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
        [alertview show];
        return YES;
    }

    return YES;

}

- (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {
    return YES;
}

- (void)collectionView:(UICollectionView *)collectionView
         performAction:(SEL)action
    forItemAtIndexPath:(NSIndexPath *)indexPath
            withSender:(id)sender {
    NSLog(@"performAction");
}

Хотя он показывает только меню «вырезать, копировать и вставить»