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iphoneuiviewuiscrollview

viewWillAppear for subviews


I have UIScrollView with multiple UIVIew subviews. I would like to update the data that is displayed by each UIView when they appear in the visible portion of the UIScrollView.

What is the callback that gets triggered? I tried viewWillAppear, but it does not seem to get called.

Thanks. :)


Solution

  • You have to do the calculation yourself. Implement scrollViewDidScroll: in your scroll view delegate and calculate manually which views are visible (e.g. by checking if CGRectIntersectsRect(scrollView.bounds, subview.frame) returns true.