App crash with 'Could not instantiate class named NSLayoutConstraint'
问题 In a .xib file how do I keep the Autolayout on for iOS 6 but off for iOS below 6. If I turn it off my .xib doesn't get the proper layout . If I turn it on my Iphone with 4.3 crashes. Any help would be appreciat it Thank you 回答1: I don't believe this is possible as autolayout changes how your application is compiled. The options I've considered for a workaround to this are: Detect the height of the display and programmatically change some of the elements (ick, but I've done this when it was