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.
Related
I'm trying to launch a application with a UI at login on windows, using the task scheduler. I've came across some inconsistencies with this, sometimes the UI will launch properly, other time it wouldn't. By adding a delay to the task, I can safely make it executed ON MY COMPUTER.
How can I ensure this correct behavior on any given computer?
Is it something to do with Windows UI not being "ready" or something like this ?
Any resource would be appreciated !
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.
I am developing a Windows Phone 8 app that would have a live flip tile. I will be creating a scheduled agent (periodic task not resource intensive) which will update the live tile using local data.
The whole app does not connect to the internet in any way, it uses only local data. So push notifications are out of the question.
I need to update the live tile from the background agent and/or from the foreground app when it's launched whichever happens first.
However how can I ensure the foreground app and the background agent do not step on each other's toes? I have two main options to do this :
Use a mutex (AFAIK the background agent runs in a different process so locks (monitor that is) is out of the question). But I'm afraid it would have a high performance cost (obtaining and releasing the mutex, that is).
When the foreground app starts I would always remove the agent, do its work and reschedule the agent back. Theferore there would not be any chance of overlapping between the foreground app and the background agent, BUT the whole add/remove agent could also be lengthy and, furthemore, the user might close the app after this removed the agent but before it added it back.
I am really torn between these two approaches and can't tell which would be best.
PS : You can't reschedule an agent from the agent's own code, right?
Mutex
The mutex option is officially recommended by the MSDN documentation for both Windows Phone 7 and 8.
I have used this option and experienced no noticeable performance problems when sharing data between the Background Agent and Foreground App, and I target WP7.1 and test on 1st and 2nd generation WP7 devices (LG E900 and Lumia 800).
Obviously, when using mutex, the key is to lock the resource for as short a time as possible. And when trying to acquire a lock on a resource in a Background Agent, the timeout feature of WaitHandle.WaitOne is very useful as the Background Agent only has 25 seconds to run.
NOTE: If you are targeting Windows Phone 8 only, or via a 2nd project/binary then a different approach (named events for inter-process-communication) is available. Peter Torr wrote about it on the official Windows Phone Developer blog.
Enabled/Disable Background Agent
The second approach you mention is riskier because the we don't know what guarantees the OS gives for adding or removing of the Background Agent - what happens if removal if not instant? what happens if a newly renewed Background Agent fires while to Foreground App is running? etc.
Agent Renewal
Background Agents cannot renew themselves - once added, they will run for a maximum of two weeks unless renewed by the Foreground App. This will prevent Background Agents running for apps the user no longer uses.
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
So my situation is that I am running an app on the Windows Task Scheduler. This app is run once a day at 1pm. the app does some queries and transfers data to an FTP site. All that is working great except on the weekends when i am not here the app is run and the GUI is still displayed for me to review. This seems to make it stop running on the scheduler until I shut down the app. So on Saturday it will run and the app will remain displayed for me to review when I get back on Monday. but on Sunday when the scheduler attempts to run it again it will fail because the app has not been closed down.
First let me confirm that this is how the Task Scheduler is supposed to work. Second, what are my alternatives for scheduling to run every day and keep the GUI displayed so that I can review. The app can run multiple times as each session does not interfere with the other sessions. So if I'm gone for a week on vacation I would expect that when i get back that 7 instances of the app have been run and are waiting for my review.
Thanks
AGP
Your best bet is to eliminate the UI and log messages to the Event Log or a log file. The UI could be spawned from the CLI as a separate process if you prefer, but it should be done so in as its own non-child process.
Alternatively, you could run a batch file instead of the process directly. In the batch file, invoke "START path_to_exe" instead of the EXE. That will cause the batch file to "finish" instantly, and the exe to be run in its own process. This is not a good long term solution, but will give you a temporary solution to your immediate problem.
This is the default behavior of the Scheduled Task system, as it doesn't know that the job is complete until the application actually exits. Therefore, if your application is still open after 24 hours, the next run will simply be skipped because the current run is "still going" as far as the scheduler is concerned.
Personally I would re-visit the way that you handle your job process, as your are setting up a scenario that will be hard to manage long term.
I recommend writing to a log file instead of displaying a UI for any output and/or errors. This way, the application can write, then exit, and you can review the log at your convenience. This is a very common solution for automated processes.