Sizeclass and autolayout, it seems that they have to give up the frame writing method.
Sizeclass Apple official documentation: https://developer.apple.com/library/ios/recipes/xcode_help-IB_adaptive_sizes/_index.html#//apple_ref/doc/uid/TP40014436
Autolayout Apple official documentation: https://developer.apple.com/library/ios/recipes/xcode_help-IB_auto_layout/_index.html#//apple_ref/doc/uid/TP40014226
Design Adaptive Layout for iPhone 6: http://www.cocoachina.com/ios/201%20/9978.htmliphone6%ratio and adapter: http://www.cocoachina.com/ios/20140912/9601.htmlSize classes with xcode 6: http://www.cocoachina.com/ios/20141015/9919.html
Swift Adaptive Layout tutorial (I): http://www.cocoachina.com/swift/20151113/9893.htmlswiftlayout (Adaptive Layout) Tutorial (II): http://www.cocoachina.com/ios/20141014/9908.html
Start Automatic Layout in iOS 7 tutorial (a): http://www.cocoachina.com/ios/20131203/7462.htmlstart iOS 7 Automatic Layout tutorial (2): http://www.raywenderlich.com/50319/beginning-auto-layout-tutorial-in-ios-7-part-2
IOS Automatic Layout -- uistackpanel and uigridpanel: http://www.cocoachina.com/ios/20141013/9898.html
There are also some blogs of great gods
Http://onevcat.com/2014/07/ios-ui-unique/
Sizeclass and autolayout