Notes

• App extensions need an arm64 slice to run on 64-bit devices. If you try to run the armv7 slice on a 64-bit device it won’t work.

• Apps need to have an arm64 slice if the bundle contains a framework that both the app and the app extension link against.

Notes

• Your app needs the iCloud entitlement to be able to be used as a document provider.

• The com.apple.developer.icloud-container-identifiers entitlement is required.

Notes

• Blood glucose data is now displayed in the Health app.

• Code that attempts to read workout information in HealthKit may be unable to make subsequent queries to HealthKit. If you are using HKWorkout, you should avoid reading workouts when running on iOS versions prior to 8.1 with:

  NSOperatingSystemVersion ios8_1_0 = (NSOperatingSystemVersion){8, 1, 0};

  if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:ios8_1_0]) {

  // Read and write workout information to HealthKit.

  } else {

  // Write workout information to HealthKit

  }

Note

URLForUbiquityContainerIdentifier: might return nil when running your application in Xcode. If so, open System Preferences, navigate to iCloud > iCloud Drive, and enable Xcode.

Note

The schedule and intended use of widgetPerformUpdateWithCompletionHandler: is as a convenient home for all data/model update logic. If implemented, the system will call at opportune times for the widget to update its state, both when Notification Center is visible, as well as in the background. An implementation is required to enable background updates. It’s expected that the widget will perform the work to update asynchronously and off the main thread as much as possible. Widgets should call the argument block when the work is complete, passing the appropriate NCUpdateResult. Widgets should NOT block returning from viewWillAppear: on the results of this operation. Instead, widgets should load cached state in viewWillAppear: in order to match the state of the view from the last viewWillDisappear:, then transition smoothly to the new data when it arrives.

Note

The NSURLSessionTask class provides a new “priority” property with three associated constants: NSURLSessionTaskPriorityDefault, NSURLSessionTaskPriorityLow, and NSURLSessionTaskPriorityHigh. NSURLSessionTask priorities can be used to specify how multiple requests and responses to the same host should be prioritized. Note that the priority is a hint and not a strict guarantee of NSURLSessionTask performance.

For complete usage details of NSURLSessionTask priorities, refer to the NSURLSession.h header file, which is provided by the Foundation framework.

Notes

• UILabel has a default value of YES for clipsToBounds. This differs from the normal UIView default of NO.

• The leftLayoutGuide and rightLayoutGuide APIs have been removed. Please use the layoutMargins property instead.

Note

The value for the WKCompanionAppBundleIdentifier key in the Info.plist of your WatchKit app must match the bundle ID of your iPhone app, or custom notification UI will not work.

Known Issues

• Creating an animated image using the UIImage method animatedImageWithImages:duration: and then playing the animation using startAnimating ignores the duration and plays back as fast as possible.

  Workaround: Use startAnimatingWithImagesInRange:duration:repeatCount: instead.

• When updating existing WKInterfaceTable row controller content and simultaneously inserting or deleting rows, indexes might lose coherence.

  Workaround: Perform all insertions and deletions before making any updates to ensure that the correct modifications are performed.