I want to get the location of my device 24x7 times. but as per apple documentation, apps can only be run for the max 10 minutes.After that, apps is automatically killed.
I am using the below code:
- (void)applicationWillResignActive:(UIApplication *)application
{
UIApplication * app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler: ^ {
dispatch_async (dispatch_get_main_queue (), ^ {
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask: bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
}];
// Start the long-running task and return immediately.
dispatch_async (dispatch_get_global_queue (DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^ {
lm.locationManager.distanceFilter = kCLDistanceFilterNone;
lm.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
[lm.locationManager startMonitoringSignificantLocationChanges];
[lm.locationManager startUpdatingLocation];
dispatch_async (dispatch_get_main_queue (), ^ {
if (bgTask != UIBackgroundTaskInvalid) {
[app endBackgroundTask: bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
});
}
I have also included supported Background Mode as Requires location.
But the app runs for only 10 minutes. How can i make the app to run all the time. Please help me out!
significantLocationChanges does not require you to implement the background task. just remove the bgtask creation and run it normally with the Supported Background Mode key.
Scheduled BackgroundTasks are killed by OS approx after 10 mins and hence your location service monitoring. So u only need to remove the BGTask that u are creating for location updates.
Related
I want to make my Application Active when Application is in background state, as my NStimer and other operation are performing. So, I did the following code to make my Application Active.
- (void)applicationWillResignActive:(UIApplication *)application
{
UIApplication *app = [UIApplication sharedApplication];
if (backgroundTaskBool==TRUE)
{
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
}];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Do the work associated with the task.
_locationManager.distanceFilter = 100;
_locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
[_locationManager startMonitoringSignificantLocationChanges];
[_locationManager startUpdatingLocation];
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
});
}
}
I just wanted to know is it a correct way to do? or there will be some other way to achieve this, because this process is taking too much battery and unnecessary location updating. So please help me out from this.
Thanks in advance.
You cant run the task in back ground for longer. IOS allow you to run the background task for 10 min only (after you click home button once your app launched).
Refer this
https://stackoverflow.com/a/5326257/1545180
As your question is tagged for iOS6!
You application cannot continue to run in background unless your application requires any of these features.
Audio—The app plays audible content to the user while in the
background. (This content includes streaming audio or video content
using AirPlay.)
Location—The app keeps users informed of their
location, even while it is running in the background.
VoIP—The app
provides the ability for the user to make phone calls using an
Internet connection.
Newsstand-content—The app is a Newsstand app
that downloads and processes magazine or newspaper content in the
background.
I am using beginBackgroundTaskWithExpirationHandler to get 10 minutes extra time for the application to run in background. But I need to stop this background task if the application comes foreground within the provided 10 minutes of time. My code is as follows
- (void)applicationDidEnterBackground:(UIApplication *)application
{
bgTask = [application beginBackgroundTaskWithExpirationHandler: ^ {
NSLog(#"invalidate back task in didenter %#",[application backgroundTimeRemaining]);
if (bgTask != UIBackgroundTaskInvalid) {
[application endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
}];
//Background tasks require you to use asyncrous tasks
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(#"\n\nRunning in the background inside DidEnterBackground %f!\n\n", [application backgroundTimeRemaining]);
while ([application backgroundTimeRemaining] > 1.0) {
NSLog(#"\n\nRunning in background %f!\n\n", [application backgroundTimeRemaining]);
sleep(5);
}
[application endBackgroundTask: bgTask];
bgTask = UIBackgroundTaskInvalid;
});
}
And when app comes foreground I am ending background task like this
- (void)applicationWillEnterForeground:(UIApplication *)application
{
[application endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
bgTask is declared globally in .h file. When app goes foreground its still running the background task with showing backgroundTimeRemaining as a long integer value. I am not getting how to stop the background task please help me.
Thanks
I am doing SMTP related app in my application, to send the mail.In IOS 4 background execution exceptions for audio,voip,location.How to use network operation.
There is no explicit exception for network access. You can request extra time to complete a task after your app exits but you can't create a daemon process that continually runs in the background.
Apple provides 600 sec to execute background task you can take help with code
UIApplication *app = [UIApplication sharedApplication];
self.bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
// Start the long-running task
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
while (1) {
NSLog(#"BGTime left: %f", [UIApplication sharedApplication].backgroundTimeRemaining);
[self.viewController performSelector:#selector(invokeCuisineSelector)];
sleep(1);
}
});
In my iPhone app I have a background task that starts running when the app enters the background state.
The task runs fine and is structured in a loop like this:
run.
sleep for 5 min.
run.
sleep for 5 min.
etc.
For some reason, the task stops running after a certain amount of time... say half an hour to an hour.
Can anyone help me understand why?
Here is the background task code:
- (void)applicationDidEnterBackground:(UIApplication *)application {
NSLog(#"Application entered background state.");
if ([[NSUserDefaults standardUserDefaults] boolForKey:#"bgCheckSwitch"] == YES) {
//UIApplication* app = [UIApplication sharedApplication];
// Request permission to run in the background. Provide an
// expiration handler in case the task runs long.
NSAssert(bgTask == UIBackgroundTaskInvalid, nil);
bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
// Synchronize the cleanup call on the main thread in case
// the task actually finishes at around the same time.
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[application endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
}];
// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Do the work associated with the task.
[someClass doSomeThing]; //The actual method performed by the task. The looping is in the method.
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[application endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
});
}
}
A background task only runs for a period of time, then the OS kills it. This is discussed in the multitasking WWDC10 videos.
Actually I am working for multitasking and facing error please assist me, as I need to work on background application and also in foreground application
- (void)applicationDidEnterBackground:(UIApplication *)application
{
UIApplication* app = [UIApplication sharedApplication];
// Request permission to run in the background. Provide an
// expiration handler in case the task runs long.
NSAssert(bgTask == UIBackgroundTaskInvalid, nil);
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
// Synchronize the cleanup call on the main thread in case
// the task actually finishes at around the same time.
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
}];
// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Do the work associated with the task.
// Synchronize the cleanup call on the main thread in case
// the expiration handler is fired at the same time.
dispatch_async(dispatch_get_main_queue(), ^{
if (bgTask != UIBackgroundTaskInvalid)
{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}
});
});
}
Put in your #interface:
UIBackgroundTaskIdentifier bgTask;
(out from NDA now).
Check out the developer documentation, if you have a developer's account. We can't really answer the os4.0 question because it's under NDA, but all the information you'll need to answer that question is on that page (once logged in).