问题
Does anyone know why I get the following message:
"The selected views have no constraints. At build time explicit left, top, width, and height constraints will be generated for the view."
I'm using XCode 5 - Storyboard with AutoLayout turned on
回答1:
Found the solution!
Select the ViewController then from the XCode menu:
Editor --> Resolve Auto Layout issues --> Add missing constraints in View Controller
回答2:
It appears that in Xcode 5.1 when using AutoLayout, when you create a new scene it will start without any editable constraints. They are generated at runtime to reflect the scene's intended layout.
So adding constraints in interface builder is not needed only if you wish to modify the defaults. When you do that you need to familiarize yourself with the provided tools (as seen in the "Resolve auto layout Issues" menu)
In a ideal wold layout just works without thinking to constraints, even if they work behind the scenes. It seems to me a step towards that goal. This is not to start a debate if the goal can be reached, only to say that we can expect more similar interface builder / xcode changes to follow.
回答3:
You have selected auto layout on your viewcontroller , so you can't set the contraints manually , uncheck the layout , it will show the constraints automatically .
来源：https://stackoverflow.com/questions/18911986/xcode-5-storyboard-has-no-constraints