UIScrollView not showing scroll indicator

Question

I have a UIScrollView which I create and size dynamically using...

scrollView.contentSize = CGSizeMake(scrollView.frame.size.width , length);

Answer 1

It will also happen (at least in the case of a UITableView) if the contentSize is too small for the table view to scroll. If you have enabled bouncing, then the tableview does not actually scroll and does not display the indicators therefore. Try fitting more content inside.

Answer 2

Two conditions,

1. If you are using a storyboard
2. If you are using a UITableView inside a UIViewController

Then, you should check your indicator insets are set to 0 (or any other number that is relevant to your autolayout):

Answer 3

Had the same problem and couldn't find the cause. The last answer gave the final hint: whenever I added new subviews I first removed all existing subviews from the scrollview (and apparently also the scroll indicators).

After checking in my loop, if the subview really was of the kind I wanted to be removed the scroll indicators showed up:

for (NSObject * subview in [[[scrollView subviews] copy] autorelease]) {
    if ([subview isKindOfClass:[MySubView class]]) {
       [(MySubView*)subview removeFromSuperview];
    }
}   

Update: changed code to Nikolai's suggestion

Answer 4

Noticed this when the UIScrollView was a 48 px tall horizontal band, scrollable horizontally. Maybe Cocoa decides the area is too small for a scroll indicator...

Answer 5

It can happen also if the parent of the scrollview is smaller horizontally than the scroll view itself :

The scroll bar is stuck to the right side of the ScrollView / TableView and this right side is not visible due to the parent bounds ( with a clipToBounds hidding it for instance).

I've seen this issue so I share it in case it can help.

Just check the width of your ScrollView's frame not to be bigger than the width of its parent view frame.

Answer 6

When I've dealt with this before, in my implementation of a grid, I would occasionally get some cells over the top of the scroll indicator. To fix this I am now inserting subviews at index 0 rather than adding them, which adds them to the top. So try something like this:

[scrollview insertSubview:subview atIndex:0];