“Auto Layout is a system that lets you lay out your app’s user interface by creating a mathematical description of the relationships between the elements. You define these relationships in terms of constraints either on individual elements, or between sets of elements.”
Size Classes let you set different constraints for certain screen sizes. This let’s you go beyond basic stretching layouts.In Xcode 6 Apple introduced Size Classes.
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
