Windows 8.1 Preview的新功能和新API

http://msdn.microsoft.com/en-us/library/windows/apps/bg182410

App打包

新的App程序包将使App的提交更简单。资源包可以让你提供附加的东西：比如高分辨率的本地化资源包。

• App resources
• App bundles
• Package identity
• App bundle deployment

异步编程

有一个新的调度API可以通过设置任务的优先级来管理作业系统（job），这就可以更有效地使用系统资源。

xaml控件的更新

包括

• AppBar controls
• CommandBar
• DatePicker
• Flyout
• Hub
• Hyperlink
• MenuFlyout
• SettingsFlyout
• TimePicker
• FlipView updates
• Headers for ComboBox, DatePicker, TimePicker, Slider, Edit controls
• Placeholder text
• Other control updates

设备

• Human Interface Device (HID) support
• Point of Service (PoS) device support
• USB device support
• Bluetooth device support

DirectX编程

windows 8.1引入了DirectX 11.2，包括以下一些新功能：

• HLSL shader linking
• Inbox HLSL compiler
• GPU overlay support
• DirectX tiled resources
• Direct3D low-latency presentation API
• DXGI Trim API and map default buffer
• Frame buffer scaling
• Multithreading with SurfaceImageSource
• Interactive Microsoft DirectX composition of XAML visual elements
• Direct2D batching with SurfaceImageSource

文件

• File picker updated to support new app display modes
• In-app management of user libraries
• Retrieving parent files or folders
• Comparing files with IsEqual
• New KnownFolders properties
• File retrieval without error-handling requirements
• Exposing view files in Open (With) scenarios
• Adding app content to the Windows index
• Microsoft SkyDrive

多媒体

• Video processing feature
• Audio and video capture feature
• XAML MediaElement
• HTML5 video and audio playback
• Play To feature

网络

• New HTTP Client API
• Custom HTTP request filters
• Background Transfer updates
• Real-time communication updates
• Connected Standby updates
• Geofence support
• Wi-Fi Direct

安全

• Fingerprint authentication
• WebAuthenticationBroker updates
• Smart cards and Virtual Smart Cards
• Credential Locker updates
• App account settings
• Trust management and certificates
• Selective wipe
• Windows To Go updates

商店

• Windows Store Dashboard and onboarding changes
• Consumable in-app purchases using Store commerce
• Support for large in-app purchase catalogs
• Automatic app updates
• Proxy authentication for enterprise scenarios
• Redeemable credit for Windows Store purchases
• Store search results powered by Bing analytics
• New and improved Store pages

工具

• General updates
• Diagnostics
• JavaScript editor
• C++ development
• HTML design tools
• XAML design tools
• Windows App Certification Kit 3.0

UX、UI

• New windowing modes
• Tile updates
• Search updates
• Share updates
• Charms work on every screen
• Integrate with people and events
• Speech synthesis
• Alarm app support on the lock screen
• Updates to work-item scheduling