上周Google I/O 2011大会最新公布的Android 3.1系统是Android 3.0 honeycomb系统的升级版，比honeycomb功能提升很多，UI也进行了调整，还心增加了Google music beta和Market电影图书购买等新功能，这些都让很多平板用户跃跃欲试。那么Android 3.1系统到底有哪些新鲜的地方呢，我们一同来盘点。
在这个新的版本中，其中的一个主要功能就是对 USB 的增强。在Google I/O上我们看到了通过 USB 游戏手柄来控制游戏的介绍，事实上除了可以使用 Xbox 手柄等设备而外，键盘、鼠标在不久的将来都可以连接到平板上。看起来这对 iPad 来说是一个强袭。
正如你可能注意到的，如果你一次打开了很多应用的话，现在可以通过上下滚动的方式来切换，当然这有一个上限就是 18 个应用，也就是最大你可以打开 18 个应用并实现滚动切换。
下面是 Xoom 更新前后的基准测试结果，你可以看一下，变化可能不是特别大，当然有提升总比没有好吧？
另外再附上一篇英文文章，对Android 3.1新功能的介绍更加详细，对于想了解Android 3.1一切的用户们请移步这里 http://developer.android.com/sdk/android-3.1-highlights.html
UI改动 – The Launcher animation is optimized for faster, smoother transition to and from the Apps list. Adjustments in color, positioning, and text make UI elements easier to see, understand, and use. Navigation to and from the five home screens is now easier — touching the Home button in the system bar now takes you to the home screen most recently used. Settings offers an improved view of internal storage, showing the storage used by a larger set of file types.
支持外接USB设备，作为USB HOST使用- Android 3.1 adds broad platform support for a variety of USB-connected peripherals and accessories. Users can attach many types of input devices (keyboards, mice, game controllers) and digital cameras. Applications can build on the platform’s USB support to extend connectivity to almost any type of USB device.
扩展了最新程序操作界面 – For improved multitasking and instant visual access to a much larger number of apps, the Recent Apps list is now expandable. Users can now scroll the list of recent apps vertically to see thumbnail images all of the tasks in progress and recently used apps, then touch a thumbnail to jump back into that task.
桌面 widgets支持自定义大小 - For more flexible Home screen customization, users can now resize their Home screen widgets using drag bars provided by the system. Users can expand widgets both horizontally and/or vertically to include more content, where supported by each widget.
支持外接键盘和其他控制设备 – Users can now attach almost any type of external keyboard or mouse to their Android-powered devices, to create a familiar environment and work more efficiently. One or more input devices can be attached to the system simultaneously over USB and/or Bluetooth HID, in any combination. For pointing devices, the platform supports most types of mouse with a single button and optionally a scroll wheel, as well as similar devices such as trackballs. When these are connected, users can interact with the UI using point, select, drag, scroll, hover, and other standard actions.
支持外接游戏手柄和 gamepads – To make the platform even better for gaming, Android 3.1 adds support for most PC joysticks and gamepads that are connected over USB or Bluetooth HID.
更稳定的WIFI连接 – A new high-performance Wi-Fi lock lets applications maintain high-performance Wi-Fi connections even when the device screen is off. Users can take advantage of this to play continuous streamed music, video, and voice services for long periods, even when the device is otherwise idle and the screen is off.
企业功能增强- Users can now configure an HTTP proxy for each connected Wi-Fi access point. This lets administrators work with users to set a proxy hostname, port, and any bypass subdomains. This proxy configuration is automatically used by the Browser when the Wi-Fi access point is connected, and may optionally be used by other apps. The proxy and IP configuration is now backed up and restored across system updates and resets. To meet the needs of tablet users, the platform now allows a “encrypted storage card” device policy to be accepted on devices with emulated storage cards and encrypted primary storage.
The Gallery app now supports Picture Transfer Protocol (PTP), so that users can connect their cameras over USB and import their pictures to Gallery with a single touch. The app also copies the pictures to local storage and provides an indicator to let users see how much space is available.
Calendar grids are larger, for better readability and more accurate touch-targeting. Additionally, users can create a larger viewing area for grids by hiding the calendar list controls. Controls in the date picker are redesigned, making them easier to see and use.
The Contacts app now lets you locate contacts more easily using full text search. Search returns matching results from all fields that are stored for a contact.
When replying or forwarding an HTML message, The Email app now sends both plain text and HTML bodies as a multi-part mime message. This ensures that the message will be formatted properly for all recipients. Folder prefixes for IMAP accounts are now easier to define and manage. To conserve battery power and minimize cell data usage, the application now prefetches email from the server only when the device is connected to a Wi-Fi access point.
An updated Home screen widget give users quick access to more email. Users can touch Email icon at the top of the widget to cycle through labels such as Inbox, Unread, and Starred. The widget itself is now resizable, both horizontally and vertically.