What's new for Windows Store device apps in Windows 8.1
Windows 8.1 brings new APIs and capabilities that you can use in your Windows Store device app. This section provides a glimpse of what's new. For more info about device apps, see Meet Windows Store device apps.
Tip Windows 8.1 also introduces new Windows Runtime device APIs that don't require device metadata. That means your app doesn't need to be a Windows Store device app to use them. Windows Store apps can use these APIs to access USB, Human Interface Devices (HID), Bluetooth GATT, Bluetooth RFCOMM, Wi-Fi Direct devices, and more. For more info, see Windows 8.1: New APIs and features.
Windows 8.1 introduces a new device metadata wizard. Easily create device metadata packages for Windows Store device apps without needing to edit raw XML. The new wizard can also validate device metadata against your app locally, before you submit it to the Dashboard. For more info about how this wizard fits into the process, see Build a Windows Store device app step-by-step.
Note To get the Device Metadata Authoring Wizard, you must install the standalone SDK for Windows 8.1 before completing the steps in this topic. Installing Microsoft Visual Studio Express 2013 for Windows installs a version of the SDK that doesn't include the wizard.
In Windows 8.1, Windows Store device apps can perform multi-step device operations in a background task so that they can run to completion even if the app is moved to the background and suspended. This is necessary to allow reliable device servicing (changes to persistent settings or firmware) and content synchronization, without requiring the user to sit and watch a progress bar. Use the DeviceServicingTrigger for device servicing and the DeviceUseTrigger for content synchronization. Note that these background tasks constrain the amount of time the app can run in the background and are not intended to allow indefinite operation or infinite synchronization. For more info, see Device sync and update for Windows Store device apps.
Note The DeviceUseTrigger, for device sync, doesn't require device metadata.
You can configure your Windows Store device app to automatically launch when your peripheral device is plugged in to the PC (after the app is installed). In Windows 8.1, AutoPlay for device apps adds support for Human Interface Devices (HID), smart cards, and the general port. For more info, see AutoPlay for Windows Store device apps.
You can see these features highlighted in the new sample, Print job management and printer maintenance. The printer extension library, that's included with the sample, wraps the COM implementation of the COM interface PrinterExtensionLib. This library was designed to make it easy to reuse in your own Windows Store device app.
To provide an experience consistent with other Windows Store apps installed on Windows 8.1, Windows Store device apps are not pinned to Start when they're installed. From Start, users can swipe up (from the center of the screen) to view all apps, including recently installed Windows Store device apps.
The Windows 8.1 built-in Camera app no longer includes an Options button. This means that a customized camera-options flyout from a Windows Store device app won't appear in that app. However, any other Windows Store app that uses the Windows.Media.Capture.CameraCaptureUI class can still expose a customized flyout for More options, when installed.