iOS8新特性

1. App Extension Programming Guide

2.LocalAuthentication.framework - Touch ID Authentication

3.Local Authentication Framework Reference.

4.Photos.framework/PhotosUI.framework

5.AV Foundation framework  拍摄大量照片简单、直接控制焦点、白平衡、曝光设置

6.使用下面API发现并使用新的6、6plus的照相机新特性。

A new property (videoHDRSupported) can determine whether a capture device supports high dynamic range streaming. 

A new video stabilization mode (AVCaptureVideoStabilizationModeCinematic) provides more
cinematic results in the captured video.

A new property (highResolutionStillImageOutputEnabled) can be used to set an AVCaptureStillImageOutput object
to capture still pictures at a higher resolution.

A new property (autoFocusSystem) can be used to determine how the camera performs auto focusing. 

7.Metal

Metal provides extremely low-overhead access to the A7 and A8 GPUs, enabling extremely high performance for your sophisticated graphics rendering and computational tasks.

you don’t need to learn multiple frameworks, languages, and tools to take full advantage of the GPU in your game or app.

10.AV Audio Engine

AVFoundation framework (AVFoundation.framework) adds support for a broad cross-section of audio functionality
at a higher level of abstraction than Core Audio. These new audio capabilities are available on both OS X and iOS and include automatic access to audio input and output hardware, audio recording and playback, and audio file parsing and conversion. You also
gain access to audio units for generating special effects and filters, pitch and playback speed management, stereo and 3D audio environments, and MIDI instruments.

For more information, see AV Foundation Framework Reference .

11.OpenGL ES

iOS 8 adds the following new extensions to OpenGL ES.

The APPLE_clip_distance extension adds support for hardware clip planes to OpenGL
ES 2.0 and 3.0. The APPLE_texture_packed_float adds two new floating-point texture formats, R11F_G11F_B10F and
 RGB9_E5.

The APPLE_color_buffer_packed_float extension builds on APPLE_texture_packed_float so
that the new texture formats can be used by a framebuffer object. This means that an app can render into a framebuffer that uses one of these formats. 

12.HealthKit Framework

HealthKit (HealthKit.framework) is a new framework for managing a user’s health-related information.

When your app implements support for HealthKit, it gets access to health-related information for the user and can provide information about the user, without needing to implement support
for specific fitness-tracking devices. The user decides which data should be shared with your app. Once data is shared with your app, your app can register to be notified when that data changes; you have fine-grained control over when your app is notified.
For example, request that your app be notified whenever users takes their blood pressure, or be notified only when a measurement shows that the user’s blood pressure is too high.  

13.HomeKit Framework

HomeKit (HomeKit.framework) is a new framework for communicating with
and controlling connected devices in a user’s home. New devices for the home are offering more connectivity and a better user experience. HomeKit provides a standardized way to communicate with those devices.

Use the HomeKit Accessory Simulator to test the communication of your HomeKit app with a device. For more information, see HomeKit Framework
Reference .

 15.Document Picker

The document picker view controller (UIDocumentPickerViewController)
grants users access to files outside your application’s sandbox .For more information, see the Document Picker Programming Guide .

 16.Handoff

Handoff is a feature in OS X and iOS that extends the user experience of continuity across devices. Handoff enables users to begin an activity on one device, then switch to another device and resume the
same activity on the other device.

17.Supporting New Screen Sizes and Scales

   Apps linked against iOS 8 and later should be prepared to support the larger screen size of iPhone 6 and iPhone 6 Plus.
On the iPhone 6 Plus, apps should also be prepared to support a new screen scale.To let the system know that your app supports the iPhone 6 screen sizes, include a storyboard launch screen file in
your app’s bundle.

iOS 8 adds new features that make dealing with screen size and orientation much more versatile.