Managing Windows 8 Metro App Lifecycle to Keep an App "Always Alive"; Windows 8 RC to be Called "Release Preview"

Microsoft will refer to the release candidate of Windows 8 under a new title following the February released of Windows 8 beta, which Microsoft described as a "Consumer Preview" version.The Windows 8 Release Candidate when launched will actually be called as the Windows 8 "Release Preview," claims WinUnleaked.tk. The site claim that the RC/RP version […]

Microsoft will refer to the release candidate of Windows 8 under a new title following the February released of Windows 8 beta, which Microsoft described as a "Consumer Preview" version.

The Windows 8 Release Candidate when launched will actually be called as the Windows 8 "Release Preview," claims WinUnleaked.tk.

The site claim that the RC/RP version of Windows 8 will be launched sometime in late May or early June.

Windows 8 Release Preview

So far, Microsoft has not said anything about its schedule for pre-release versions of Windows 8, nor any word on what those builds will be called. In any case, Microsoft is still apparently sticking with its plans to launch the final shipping version of Windows 8 in late 2012, possibly sometime in October.

Also, in a April 10 blog post, Microsoft offers tips to Windows 8 Metro app developers on Managing app lifecycle so your apps feel "always alive".

"The app lifecycle model in Windows 8 means that users no longer need to manage which apps are running. It also makes it easy for developers to craft a great user experience that doesn't affect the device's battery or performance when the app is in the background. Using the new lifecycle events, your app will always feel alive, even though it never runs when it is off-screen," posted Adam Barrus, Program Manager, Windows.

There are four parts to a Windows 8 Metro lifecycle states at any given time: Not running, running , suspended or terminated. "As your app transitions between states, it receives lifecycle events that help you provide a consistent and high performance experience to your users," writes Barrus.

The diagram below shows how a Metro style app transitions between states. All Metro style apps move through these states as users launch apps, switch among them, and close them. "Your app will likely move between the running and suspended states quite often as users switch between apps. So, your app must handle the lifecycle events. In general, Metro style apps stop running when the user switches to another app. Windows suspends your app when it is not in the foreground. When your app is suspended, it is frozen in memory. It can't run in this state, but Windows can instantly resume it when the user returns to it," Barrus explains.

Windows 8 Metro style app transitions between states

He notes, "Metro style apps in Windows 8 must never close themselves or present app UI to allow a user to close your app. Suspending and terminating apps is handled by Windows on the user's behalf to maintain system performance and battery life. If users want to close your app, they can do so by swiping from the top to the bottom of the screen or by pressing ALT+F4."