问题
I installed Xcode 6 gm version. I created new project and I run it on iPhone 6 or iPhone 5s simulator with ios 8. Everything is fine.But When I simulate on iphone 5s deployment target ios 7.1.Device screen is not full screen.it runs like as 3.5inc screen.Do you know reason of that? Is it XCode 6's bug?

回答1:
you should put launch screen for iphone 5 - 640x1136 named Default-568h@2x or use catalog assets alternatively.
回答2:
Figured out a solution in my case
- Go to General tab of project's target
- Scroll down to App Icons and Launch Screens section
- Click on Use Asset Catalog drop down option under Launch Images Source
- In prompt choose Migrate - this will create LaunchImage category under .xcassets image set (default Images.xcassets in my case)
- Launch the app - ifullscreen issue gone in my case

来源:https://stackoverflow.com/questions/25870612/simulate-on-xcode-6-somethings-wrong