UIScrollView doesn't scroll - even with valid content size and scroll enabled - uiscrollview

Question

In my viewDidAppear method (in which i call to the super method) I have the following code:
UIScrollView *navbar = [[UIScrollView alloc] init];
[navbar setScrollEnabled:YES];
[navbar setBackgroundColor:[UIColor redColor]];
[navbar setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addSubview:navbar];
NSDictionary *viewsDictionary2 = NSDictionaryOfVariableBindings(navbar);
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|[navbar]|"
options:0
metrics:nil
views:viewsDictionary2]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[navbar]|"
options:0
metrics:nil
views:viewsDictionary2]];
NSArray *categories = #[#"nav1", #"nav2", #"nav3", #"nav4", #"nav5", #"nav6", #"nav7", #"nav8", #"nav9", #"nav10", #"nav11", #"nav12", #"nav13"];
NSMutableArray *tempCategoryImages = [NSMutableArray array];
for (NSInteger i = 0; i < categories.count; i++)
{
[tempCategoryImages insertObject:[UIImage imageNamed:categories[i]] atIndex:i];
}
NSArray *categoryImages = [tempCategoryImages copy];
// Add subviews.
//
CGFloat xPadding = 25.0f;
UIView *previousImageView = NULL;
for (NSInteger i = 0; i < categoryImages.count; i++)
{
UIImageView *imageView = [[UIImageView alloc] initWithImage:categoryImages[i]];
[imageView setTranslatesAutoresizingMaskIntoConstraints:NO];
[navbar addSubview:imageView];
if (i == 0) {
//
// First category.
//
[navbar addConstraint:[NSLayoutConstraint constraintWithItem:imageView
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:imageView.superview
attribute:NSLayoutAttributeLeft
multiplier:1
constant:0]];
} else {
//
// End categories.
//
[navbar addConstraint:[NSLayoutConstraint constraintWithItem:imageView
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:previousImageView
attribute:NSLayoutAttributeRight
multiplier:1
constant:xPadding]];
}
[navbar addConstraint:[NSLayoutConstraint constraintWithItem:imageView
attribute:NSLayoutAttributeCenterY
relatedBy:NSLayoutRelationEqual
toItem:imageView.superview
attribute:NSLayoutAttributeCenterY
multiplier:1
constant:0]];
previousImageView = imageView;
}
// Set content size.
//
CGSize scrollContentSize = CGSizeZero;
for (NSInteger i = 0; i < categories.count; i++)
{
UIImage *tempImage = [UIImage imageNamed:categories[i]];
// Width.
//
scrollContentSize.width += tempImage.size.width;
// Height.
//
if (tempImage.size.height > scrollContentSize.height) {
scrollContentSize.height = tempImage.size.height;
}
}
navbar.contentSize = scrollContentSize;
Which when i log the scrollviews properties, it has the subviews, a large enough content size and scrolling enabled.
Even when I add the UIScrollView to IB and link it to the same code it then works? (I comment out the NSAutoLayout code.
This leads me to believe that for the UIScrollView to work, I cannot use Auto layout.
Am I missing something?
Thanks
EDIT
The code also doesn't work programatically, when I try initWithFrame:frame with setTranslatesAutoresizingMaskIntoConstraints:YES

Answer 1

Check the attributes inspector for your scrollview in IB. Make sure that bounce vertically is checked.
Fixed this problem for me.