ViewController加载完成以后，旋转屏幕，会触发以下事件：
注：ShowViewCycle是ViewController的SubView
1. -[ViewController willTransitionToTraitCollection:withTransitionCoordinator:] [Line 76] newCollection:<UITraitCollection: 0x7f8f22d6a5a0; _UITraitNameUserInterfaceIdiom = Phone, _UITraitNameDisplayScale = 2.000000, _UITraitNameHorizontalSizeClass = Compact, _UITraitNameVerticalSizeClass = Compact, _UITraitNameTouchLevel = 0, _UITraitNameInteractionModel = 1> coordinator:<_UIViewControllerTransitionCoordinator: 0x7f8f22d67660>
2. -[ViewController viewWillTransitionToSize:withTransitionCoordinator:] [Line 63] coordinator:<_UIViewControllerTransitionCoordinator: 0x7f8f22d67660>, size 667.000000 hight:375.000000
2.1 -[ShowViewCycle translatesAutoresizingMaskIntoConstraints] [Line 393]
2.2 -[ShowViewCycle translatesAutoresizingMaskIntoConstraints] [Line 393]
2.3 -[ShowViewCycle translatesAutoresizingMaskIntoConstraints] [Line 393]
3. -[ViewController viewWillLayoutSubviews] [Line 186]
4. -[ViewController updateViewConstraints] [Line 387]
4.1 -[ShowViewCycle translatesAutoresizingMaskIntoConstraints] [Line 393]
4.2 -[ShowViewCycle alignmentRectInsets] [Line 434]
5. -[ViewController viewDidLayoutSubviews] [Line 196]
5.1 -[ShowViewCycle layoutSubviews] [Line 231]