Not called button after adding in to container - ios

Question

I have container view, where I add some image and button.
Container view is property of UIView.
I'll add my Container View to ScrollView like this:
#property (nonatomic,strong) UIView *containerView;
..
containerView = [[UIView alloc] init];
for (int i=0;i<5;i++) {
UIImageView *whiteBack = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 235-height, 385-height-height)];
whiteBack.center = CGPointMake(_scrollView.frame.size.width * i+_scrollView.frame.size.width/2, self.view.bounds.size.height/2-131+height);
whiteBack.backgroundColor = [UIColor darkGrayColor];
whiteBack.layer.cornerRadius = 3;
whiteBack.layer.masksToBounds = YES;
[containerView addSubview:whiteBack];
UIImageView *img = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 228-height, 340-height-height)];
img.center = CGPointMake(_scrollView.frame.size.width * i+_scrollView.frame.size.width/2, self.view.bounds.size.height/2-150+height);
img.image = [UIImage imageNamed:[NSString stringWithFormat:#"poster0%i.jpg",i+1]];
[containerView addSubview:img];
UIButton *infoButton = [UIButton buttonWithType:UIButtonTypeCustom];
infoButton.frame = CGRectMake(233, 0, 25, 25);
infoButton.center = CGPointMake(_scrollView.frame.size.width * i+_scrollView.frame.size.width/2-100, 325-height);
[infoButton addTarget:self action:#selector(flipImage:) forControlEvents:UIControlEventTouchUpInside];
infoButton.tag = i;
infoButton.backgroundColor = [UIColor clearColor];
[infoButton setImage:[UIImage imageNamed:#"upload-50"] forState:UIControlStateNormal];
[infoButton setTintColor:[UIColor whiteColor]];
[containerView addSubview:infoButton];
}
[self.scrollView addSubview:containerView];
///
- (void) flipImage :(id) sender {
NSLog(#"infoButton pressed:%i",[sender tag]);
}
but when I pressed button nothing happens!

Answer 1

Your container view has a zero frame (because you just did [[UIView alloc] init];). This means that it never receives any touches because you can never hit it. This goes for the subviews too.
The reason you see the subviews is that views, by default, do not clip drawing to their bounds.
To fix, set the frame of your container view to an appropriate size for the subviews you're adding.