Run app for more than 10 minutes in background

问题

I am trying to keep the iOS app in active state for more than 10 mins when it enters in background state.

How can I implement this.

回答1:

See "Background Execution" section of the iPhoneAppProgrammingGuide. In short, your app must be one of these types:

Apps that play audible content to the user while in the background, such as a music player app
Apps that keep users informed of their location at all times, such as a navigation app
Apps that support Voice over Internet Protocol (VoIP)
Newsstand apps that need to download and process new content
Apps that receive regular updates from external accessories

And you must add to the Info.plist as follows: Add the UIBackgroundModes key to your Info.plist file and set its value to an array containing one or more of the following strings:

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 aNewsstand app that downloads and processesmagazine or newspaper content in the background.
external-accessory—The app works with a hardware accessory that needs to deliver updates on a regular schedule through the External Accessory framework.
bluetooth-central—The app works with a Bluetooth accessory that needs to deliver updates on a regular schedule through the CoreBluetooth framework

Note that part of the review process will be checking to make sure that your app does what it says it's doing with regard to background processing.

回答2:

Here's what I've done using beginBackgroundTaskWithExpirationHandler.

Write a method that starts a background task.
Inside that background task, run a NSTimer with a scheduled (non repeating) time that is under 10 minutes. For the purposes of my situation I was using 5 minutes.
Once the NStimer's selector fires, end the background task and then instantly call the method that you wrote earlier to start off another background task.
If you want to schedule methods to run at specific times, you will have to check for them in the background task.

This solution isn't really ideal and is still power hungry but will do what you want.

Edit: Since iOS7, I suggest you read this excellent post. Note that this article was last updated in 2013 and is probably irrelevant now.

回答3:

Only certain types of apps are allowed to run in the background. See the "Implementing Long-Running Background Tasks" section of this guide.

If you aren't requesting permissions to do background processing you can use UIApplication's beginBackgroundTaskWithExpirationHandler but you cannot get extra time.

回答4:

This code makes your iOS app run indefinitely in the background. Copy and paste the below methods into a singleton / manager which handles the tasks you need to perform in the background.

// @interface

// Declare Private property
@property (nonatomic) UIBackgroundTaskIdentifier backgroundTask;

//@end
// ...

// Copy into
//@implementation 

- (void)setupBackgrounding {
    [[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(appBackgrounding:)
                                                 name: UIApplicationDidEnterBackgroundNotification
                                               object: nil];
    [[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(appForegrounding:)
                                                 name: UIApplicationWillEnterForegroundNotification
                                               object: nil];
}

- (void)appBackgrounding: (NSNotification *)notification {
    [self keepAlive];
}

- (void) keepAlive {
    self.backgroundTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
        [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTask];
        self.backgroundTask = UIBackgroundTaskInvalid;
        [self keepAlive];
    }];
}

- (void)appForegrounding: (NSNotification *)notification {
    if (self.backgroundTask != UIBackgroundTaskInvalid) {
        [[UIApplication sharedApplication] endBackgroundTask:self.backgroundTask];
        self.backgroundTask = UIBackgroundTaskInvalid;
    }
}

回答5:

https://github.com/yarodevuci/backgroundTask Check my code here I am using audio player that plays blank wav file Works perfectly on IOS 8 Battery usage around 10% in 24 hour period How to use:

var backgroundTask = BackgroundTask()
backgroundTask.startBackgroundTask() //Starts playing blank audio file. You can run NSTimer() or whatever you need and it will continue executing in the background.

backgroundTask.stopBackgroundTask() //Stops the task

Warning: Apple will reject this if you try to submit it!

回答6:

You can't. Unless your app uses audio, voip or gps. What you can do is notify the user (via local notifications) that the time is almost up and ask him to open/close the app.

Also if you just need to notify the user, you can use push notifications.

回答7:

If your App type is not one of VOIP/Audio/Location....(check Background Modes),

or you don't want to specify your App as a background App, you can implement beginBackgroundTaskWithName:expirationHandler or beginBackgroundTaskWithExpirationHandler to ask for more time to run your process in background. You can find the detailed description here

Apps moving to the background are expected to put themselves into a quiescent state as quickly as possible so that they can be suspended by the system. If your app is in the middle of a task and needs a little extra time to complete that task, it can call the beginBackgroundTaskWithName:expirationHandler: or beginBackgroundTaskWithExpirationHandler: method of the UIApplication object to request some additional execution time. Calling either of these methods delays the suspension of your app temporarily, giving it a little extra time to finish its work. Upon completion of that work, your app must call the endBackgroundTask: method to let the system know that it is finished and can be suspended.

Each call to the beginBackgroundTaskWithName:expirationHandler: or beginBackgroundTaskWithExpirationHandler: method generates a unique token to associate with the corresponding task. When your app completes a task, it must call the endBackgroundTask: method with the corresponding token to let the system know that the task is complete. Failure to call the endBackgroundTask: method for a background task will result in the termination of your app. If you provided an expiration handler when starting the task, the system calls that handler and gives you one last chance to end the task and avoid termination.

来源：https://stackoverflow.com/questions/9738488/run-app-for-more-than-10-minutes-in-background

标签

ios

background-process