Making the app bar accessible
[This article is for Windows 8.x and Windows Phone 8.x developers writing Windows Runtime apps. If you’re developing for Windows 10, see the latest documentation]
The app bar is important because it gives the user easy access your app's commands.
If you use platform button elements (Windows Runtime button controls in HTML, any ButtonBase class in XAML, keyboard activation is already supported.
The app bar is also an excellent place to put alternatives for functionality that is otherwise difficult to expose for accessibility. For example, consider the transport controls in a custom media player app:
Because these controls are used frequently, the app designers decided to expose them in the app bar. Having these controls as buttons in the app bar gives the user an easy way to control music and videos with the keyboard and Narrator. This is especially convenient on touch-only devices. Finding on-screen transport controls can be a challenge for blind and visually impaired users because the default transport controls disappear after a few seconds while the media is playing. (This is the behavior of the built-in transport controls in the XAML MediaElement, with AreTransportControlsEnabled=true).