Editor’s note: If you’ve downloaded the Xcode 6 beta and played around with it, one thing you may notice is the change of Interface Builder. The default view controller is now wider and doesn’t look like an iPhone 5. When you position a button in the center of the view and run the app, it doesn’t look good. The button is not centered properly.
What’s wrong? How can you make it right? The answer is Auto Layout. Auto Layout is a constraint-based layout system. It allows developers to create an adaptive interface that responds appropriately to changes in screen size and device orientation. We seldom talk about Auto Layout in our tutorials. Some beginners find it hard to learn and avoid using it. Starting from Xcode 6, you should learn to love Auto Layout. Apple is expected to release 4.7-inch and 5.5-inch iPhone 6 this fall. Without using Auto Layout, it would be very hard for you to build an app that supports all screen sizes.
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