how to play alarm audio once in Windows Phone 8? - windows-phone-7

When I try to use alarms to launch voice from my application when it doesn't run in determined times I face a problem.
The audio still running more than one time as I only want it to run once. But it continuo running until the user stop it which is not suitable for my application behavior.
So, is there a way to make alarm audio file run only once in this time?
If no, is there any other way to do that instead of alarms?

Alarm are programmed to be repeated forever. You can't unless you change something in the audio file.

Related

Is there a api function for a MacOS Store based application to start itself at a certain time

Under Windows i use the Task Scheduler, under linux cron job to start an application at a certain time, even if the cron job would work on MacOS, i wonder if there is a apple conform way to start my application at certain times and to start the computer from hibernation.
I know that cron jobs would work, but i doubt that this would ever pass its way through a apple review.
The reason for this question is that the application is working a tv player with the ability to record DVB transmissions. I dislike the idea to "force" the user to keep the program running in background.

Allow computer to sleep while playing audio from a Windows application

I am working on a Windows 10 application that plays audio in the background. What I would like to be able to do is allow the computer to still go in to Sleep Mode while the audio is playing (as in, Power & Sleep Settings, Sleep after XX minutes). And by this, I mean stop playing the audio and go to Sleep (not continue playing while in Sleep). Is this even possible? Searching online hasn't been fruitful, as I can pretty much only find information on how to prevent Sleep, not enable it.
Running powercfg.exe /requests shows the audio playback is indeed preventing sleep:
SYSTEM:
[DRIVER] Realtek High Definition Audio (...)
An audio stream is currently in use.
I am currently using the IAudioClient and IAudioRenderClient interfaces for playback, via client->Start(), renderClient->GetBuffer(). I could switch to a different API if necessary. However, whatever I use needs to allow other applications (VLC, YouTube, Windows sounds, etc.) to play audio as normal at the same time.
My application is always running on the system I'm using it on, and I simply want the system to be able to go to Sleep at the set system timeout. I also need to apply this exception to my application only - if other applications are playing audio that would prevent Sleep, the system should not Sleep.
Are there any Windows API calls that can make Windows ignore my application playing audio and still let the system go into Sleep Mode?
What you are asking for is not possible today. When the system goes to sleep, it essentially means that the processors in your system stops executing any instructions and powers down. Although this is not like shutting down the system, it is very close to it. All the devices connected to the processors are also powered down to save the battery/power consumption.

UWP apps running background tasks when the app is closed

I want to run a background task for every 10 mins.As the UWP app will not always be opened.Is there a way to run a background task even when the app is closed(Not Running State)?
If the answer is NO,
Is there any another way other than Windows Services?
You can create BackgroundTask which run at the most every 15 minutes not less than that in UWP apps. for more details you can check this source.
Is there a way to run a background task even when the app is
closed(Not Running State)?
According to this document:
You can use background tasks to provide functionality when your app is
suspended or not running.
The 'not running' state in UWP is described in more detail here. It reads:
An app could be in this state because it hasn't been launched since
the last time the user rebooted or logged in. It can also be in this
state if it was running but then crashed, or because the user closed
it earlier.
This implies that the app simply needs to run once after installation to be able to successfully register a background task, which can then run even after your app is closed.
I want to run a background task for every 10 mins
Not sure I'm interpreting this correctly but I assume you mean you want to run some bit of code every 10 mins while your app is not running. Well there are two way that I can think of to achieve this.
Method 1:
While background tasks are meant to be very short-lived tasks, they may even be made to run indefinitely if:
extendedBackgroundTaskTime capability is added as a restricted
capability in your app's manifest file
Using this technique along with a simple timer mechanism would achieve the desired result.
Method 2 (more complicated but keeps background tasks short-lived):
Setup a DatagramSocket to a remote server which sends some data every 10 mins and register your background task with a SocketActivityTrigger.

How can you update location data in Windows Phone in the background?

I just read that while Windows Phone 7.5 background tasks can poll for a location, they don't actually poll real-time from the GPS but rather the location API calls return a system-cached position that's only updated once every fifteen minutes.
That limitation of course completely invalidates any attempt at having navigation run in the background as you can get pretty damn far off-track in fifteen minutes, let alone that a background task can only run once every thirty minutes or so!
That said, Nokia's navigation app and reportedly Runtastic's app do continue tracking when in the background (i.e. not just under the lock screen) and both are in the marketplace meaning they have been approved, so does anyone know how they managed to do what the SDK supposedly doesn't support?
For reference, we don't actually need real-time tracking... maybe once a minuted or so, and we don't need that much accuracy... maybe 100 feet or so... but we do need more than we have been given. We just don't know how they're doing it in approved apps.
You'll only be able to retrieve the location when your PeriodicTask executes (Approximately every ~30 minutes, depending on OS scheduling). The location data it fetches from GeoCoordinateWatcher will be from the OS's cache rather than directly from the GPS hardware. If nothing is running the OS will update this with coarse-grained data approximately every 15 minutes. However if an application has executed and retrieved fine-grained GPS hardware data than this will be the data you'll retrieve in your PeriodicTask. You can see examples of this by accessing the GPS in your foreground app and force-scheduling your PeriodicTask with ScheduledActionService.LaunchForTest.
Based on my experience with background tasks, you will not be able to achieve what you want with either Periodic or ResourceIntensive background tasks.
Despite documentation claiming that they run every 30 minutes, my experience is that they run sporadically and unpredictably. Over the last 14 hours, my app's periodic task has run a total of 6 times, and this is pretty consistent every day - it runs about once every two hours. For resource intensive tasks, I find they usually run about twice a night. I guess the OS has to balance all the processes on the phone and all the other apps clamoring to run their background tasks, so sometimes yours doesn't make the cut. Obviously, your mileage may vary based on your phone (lumia 800 in my case) and the apps you have installed.
If you want to write an app that tracks your location once a minute, my advice would be to enable it to run under the lock screen by disabling idle detection and make sure it has a low memory footprint to conserve battery life.

Using timed events in BlackBerry

is it possible to fire up an event at a specified time interval in BlackBerry? I'm looking for something similar to AlarmManager class in Android (if anyone is familiar with it).
The goal is to is to run some code, even when the application is not in foreground and without it gaining foreground "focus". Preferably it should be possible to fire the event even if the app was killed by system or by phone reboot (I do not know the details about killing apps at this OS, I'm beginning development now).
I would prefer not to write a background process for this task as it is going to be fired every few hours (I think it would be a waste of battery to use a background task for a simple alarm-like event).
I've looked around a lot, but I cannot find any satisfying solution.
cheers,
kajman
The Timer and TimerTask classes are useful for running a task on a schedule. Take a look at the APIs here:
http://www.blackberry.com/developers/docs/7.0.0api/java/util/Timer.html
The Timer will create its own Thread and sleep until it has a task to run. It would involve having a background task running but it wouldn't be using an CPU or battery if it is just waiting.
If you don't want a Thread running all of the time you can use the ApplicationManager class to schedule your application to start later.
You can also configure your app to run on start up. The OS generally won't kill your apps unless you have a coding error. RIM refers to this as the Always-On Experience in their Super App document:
http://docs.blackberry.com/en/developers/deliverables/23567/Always_on_1380986_11.jsp#Keeping_the_app_running_1381022_11

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