ios设置app初始化的背景图片Launch Images

Using a Launch Screen StoryboardDEC 24TH, 2014 STORYBOARD, XCODE

Static Launch Images

Launch images are what iOS displays whilst loading an App to give the impression of a responsive system. Creating these static launch images for the growing number of screen resolutions has become something of a pain in recent years. At the time of writingthe list of possible launch image sizes is below (sizes include the status bar region). I have omitted the landscape versions for brevity:iPad 2 and iPad mini (@1x): 768 x 1024iPad and iPad mini (retina @2x): 1536 x 2048iPhone 4s (retina @2x) 640 x 960iPhone 5 (@2x): 640 x 1136iPhone 6 (@2x): 750 x 1334iPhone 6 Plus (@3x): 1242 x 2208There is some good news with Xcode 6 and iOS 8 which allow a NIB or storyboard launch screen file to be used. By taking advantage of auto layout and size classes a single NIB or storyboard file automatically creates the launch images at runtime. Notethat if you want to properly support the larger iPhone 6 and iPhone 6 Plus screen sizes in fullscreen mode without scaling you must supply the appropriate launch images either as static images of dimensions as listed above or with a storyboard launch screenfile.(Updated 26-Dec-2014: made it clearer that supporting iPhone 6 and iPhone 6 Plusrequires you to provide the launch images but they can be static image files or from a launch screen file).

Using a Launch Image File

Xcode 6 adds a LaunchScreen.xib file by default to new projects. For an existing project add a new file using the Launch Screen template:Note that this will add a NIB file to the project which is fine if you have a single view or view controller on the initial launch screen. If you have multiple views you will need to ignore the launch screen template and add a storyboard. You should also specifythe launch screen file in the project settings for the target:This will add the Launch screen interface file base name (UILaunchStoryboardName) keyto the application plist file:At this point you can layout the launch view in Interface Builder using autolayout and size classes as necessary to create suitable images for each screen resolution. The Xcode template does not provide a very good example as it provides a splash screen stylelayout with the app name and copyright statement that you will probably want to delete before adding your own view layout:You can preview the storyboard in Xcode or test it in the simulator or on an actual device. Since the launch screen is only briefly displayed you may find it useful to set a breakpoint on application:didFinishLaunchingWithOptions: in the App delegate.原文:http://useyourloaf.com/blog/using-a-launch-screen-storyboard.html