IPhone: adding a button to scrollview makes the button inaccessible for interaction

Question

For some reason, the button initialized in the addBook method of my viewController will not respond to touch. The selector that I assigned to it never starts, and the UIControlStateHighlighted image never appears when I click on the image.

Are there any catching touches before they get into UIButton, or is its interactivity somehow turned off by what I'm doing with it?

- (void)viewDidLoad {

    ...

    _scrollView.contentSize = CGSizeMake(currentPageSize.width, currentPageSize.height);
    _scrollView.showsHorizontalScrollIndicator = NO;
    _scrollView.showsVerticalScrollIndicator = NO;
    _scrollView.scrollsToTop = NO;
    _scrollView.pagingEnabled = YES;

    ...
}

- (void)addBook {
    // Make a view to anchor the UIButton
    CGRect frame = CGRectMake(0, 0, currentPageSize.width, currentPageSize.height);
    UIImageView* bookView = [[UIImageView alloc] initWithFrame:frame];

    // Make the button
    frame = CGRectMake(100, 50, 184, 157);
    UIButton* button = [[UIButton alloc] initWithFrame:frame];
    UIImage* bookImage = [UIImage imageNamed:kBookImage0];

    // THIS SECTION NOT WORKING!
    [button setBackgroundImage:bookImage forState:UIControlStateNormal];
    UIImage* bookHighlight = [UIImage imageNamed:kBookImage1];
    [button setBackgroundImage:bookHighlight forState:UIControlStateHighlighted];
    [button addTarget:self action:@selector(removeBook) forControlEvents:UIControlEventTouchUpInside];

    [bookView addSubview:button];   
    [button release];
    [bookView autorelease];

    // Add the new view/button combo to the scrollview.
    // THIS WORKS VISUALLY, BUT THE BUTTON IS UNRESPONSIVE :(
    [_scrollView addSubview:bookView];
}

- (void)removeBook {
    NSLog(@"in removeBook");
}

The view hierarchy looks like this in Interface Builder:

UIWindow
UINavigationController
    RootViewController
        UIView
            UIScrollView
            UIPageControl

and presumably how this happens when using the addBook method:

UIWindow
UINavigationController
    RootViewController
        UIView
            UIScrollView
                UIView
                    UIButton
            UIPageControl

Answer 1

Answer 2

[bookView autorelease]; :

// Add the new view/button combo to the scrollview.
// THIS WORKS VISUALLY, BUT THE BUTTON IS UNRESPONSIVE :(
[_scrollView addSubview:bookView];
[bookView release];

_scrollView.canCancelContentTouches = YES;

delaymentsContentTouches - , , touch-down. YES, , , . NO, touchsShouldBegin: withEvent: inContentView:. : YES.

canCancelContentTouches - , , . YES, , , , Cancelled: withEvent: . NO, .