ios - What conditions can prevent layoutSubviews from being called after setNeedsLayout? -
the problem in custom view of mine (a uiscrollview subclass) calling setneedslayout in response "reload data" event (triggered external source). of time works correctly , layoutsubviews called when next view layout cycle occurs. sometimes, however, layoutsubviews not called! until living "certain knowledge" setneedslayout always triggers layoutsubviews . apparently wrong. tried calling layoutifneeded after setneedslayout , still no success. the question obviously, solve particular problem. on other hand, improve understanding of view layout process on ios, formulating question in general way: know of conditions can prevent layoutsubviews being called after setneedslayout has been called? answers focus on uiscrollview quite welcome, since having trouble. problem context i on ios 7.1, using xcode 5.1.1. notes on implementation of custom scroll view: the scroll view has single container view of type uiview same size scroll view content size ...