Managing app lifecycle so your apps feel "always alive"

re: Managing app lifecycle so your apps feel "always alive"

Manoj — Mon, 04 Jun 2012 04:07:52 GMT

How does Windows 8 keep track of active application and which service or component in Windows 8 controls application lifecycle?

re: Managing app lifecycle so your apps feel "always alive"

David A Nelson — Mon, 30 Apr 2012 15:02:02 GMT

"Sometimes it’s best to start fresh...In your resume handler, check how old the current article is to determine if it is now stale. If the article is too old, display your default home view instead of the old article."

For the love of your users, NEVER do this! As the application developer it is highly unlikely that you will be able to accurately determine when any content is "too stale" for the user. The Safari mobile browser is a prime example; sometimes (I have yet to determine what criteria it uses) when you switch to the browser, the page reloads. But if I happen to be in a place where I have limited or no connectivity, the page fails to load; so that article that I was in the middle of reading, and could have continued reading since it was already loaded in my browser, is now inaccessible.

This is a great example of the shift of the entire Microsoft ecosystem away from user control. The USER should decide when content should be refreshed, not the developer. Give the user a refresh control; even give them a warning that the content is outdated if you want. But NEVER remove content that that the user has loaded because you think the user won't want it anymore; let the user tell you when to do that.

re: Managing app lifecycle so your apps feel "always alive"

Slawa Konkevych — Sun, 29 Apr 2012 21:04:33 GMT

Very important post for me as I try to figure out how the lifecycle of Metro Apps is managed.

@Adam, I'm wondering whether an API exists to monitor and control Metro App externally?

Thank you in advance.

re: Managing app lifecycle so your apps feel "always alive"

Hosam Kamel — Wed, 18 Apr 2012 20:50:26 GMT

Very clear and important for Metro developers

re: Managing app lifecycle so your apps feel "always alive"

Jeff Sanders — Wed, 18 Apr 2012 20:09:46 GMT

@Andrew, when you are debugging an app in the tool bar you will see a set of 3 icons - a VCR style Pause, Play and Stop button. Hover over those with a mouse and can see they are 'Suspend', 'Resume' and 'Suspend and shut down the application' respectively. -Jeff

re: Managing app lifecycle so your apps feel "always alive"

Andrew — Tue, 17 Apr 2012 18:44:01 GMT

@Adam, could you please point me to the right "debugging controls" in VS11 (I'm lost)

re: Managing app lifecycle so your apps feel "always alive"

Adam Barrus [MSFT] — Thu, 12 Apr 2012 17:48:18 GMT

Paul:

Thanks for your comment. Detailed information about how Metro style apps can run code when in the background is available in the Introduction to Background Tasks whitepaper, which you can find at go.microsoft.com/fwlink.

re: Managing app lifecycle so your apps feel "always alive"

Adam Barrus [MSFT] — Thu, 12 Apr 2012 17:36:37 GMT

Mike:

Thanks for your comment. Visual Studio has controls in its debugging experience that allow a developer to suspend, resume and terminate a Metro style app. You can use this today with the version of Visual Studio that shipped with the Windows 8 Consumer Preview. Using these controls, you can simulate these important app lifecycle events in your development environment and in your app. It is important to note that an app under debugging in Visual Studio will not receive these app lifecycle events unless they are triggered by the included controls mentioned previously.

re: Managing app lifecycle so your apps feel "always alive"

Paul — Wed, 11 Apr 2012 18:41:01 GMT

I'm puzzled by the Suspend mode. "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." How is this going to work for programs which often do useful work in the background? Play music? New e-mail notification? Network monitoring? Are these exceptions to the "in general"?

re: Managing app lifecycle so your apps feel "always alive"

Mike — Tue, 10 Apr 2012 23:48:17 GMT

Great, great post. Really clear and really important for developers to understand from day 1 :-)

One thing I'd add is that it would be good if you could mention how the debugger plays into all of this because I think it confuses a lot of people who are new to these apps.

Mike.