I am trying to do an app which make a song sing at a time set by the user. The user should set the time by opening the app. Even after the user force kills the app after setting the time, I must be able to make the song sing at the particular time. How do I do this?
You can do this but not without user interaction if your app is not running.
Set Local Notification for time which user set.
At that time your app will be notified by two way
1 If your app is running : didReceiveLocalNotification:(UILocalNotification *)notification
2 If your app in not running : didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
And you can play song from here.
To learn you can visit this :
iPhone Programming Tutorial – Local Notifications
iOS Multitasking: Local Notifications
To be able to play the song also when force quitting you need to do this by push notifications.
You can add the small sound to the Push Notification. So you need to store the sound snippet and the time on the server and trigger a push notification with the sound attached on the server. Or using LocalNotifications.
This will do the trick for you. Otherwise you can just play the sound if the app is running.
Related
I'm using local and silent remote notifications in the app I'm working at work. I need to launch some methods according to events received from our servers or from the app itself via silent remote and local notifications respectively. I have no problem with remote notifications with the app in foreground, background or with the notification touched but I can't get the scheduled local notifications to be noticed by AppDelegate if the app is running in background (I mean, without user tapping the banner).
Is this even possible? If yes, which parameter should I add to the notification or what method is supposed to be called when it arrives?
I don't think it's possible to send a local notification that runs silently and starts your app. The normal way to do things like this is Background App Refresh:
https://developer.apple.com/documentation/uikit/app_and_environment/scenes/preparing_your_ui_to_run_in_the_background/updating_your_app_with_background_app_refresh
You have no control of the time. iOS will periodically give you short slices of time
I am writing an alarm clock app for iphone, and I want it to turn on the phone(from standby mode) approx 1hr before the alarm is supposed to go off.
Then I want the app to be active, so I can stream content live without the user having to put the phone in an active-mode.
Any way for an app to switch out of standby?
Without using private api an application can only present alertview (via local or push notification).
And only when user taps "view" button this application can be activated. You can see that in the link you provided - (second to last screenshot)
True, you can always add sound to this notifications - so alarm app can work (and there are many out there) but it can't send itself in the foreground.
Nope that cant be done, once the app went to the background state you lose control on it, and cannot bring it back
There might be a way using notifications. Check this SO question for more info:
Alarm Even Application Closed in iPhone
My app connects to a Bluetooth sensor then starts updating the UI based on the notifications sent from said device. I am having a problem with IOS automatically generating a large amount of notification pop-ups when the app is minimized, I think this is due to the frequency at which the sensor is sending data. So I am trying to figure out how to keep the user from being bombarded when they minimize the app. I am trying to tell the device to stop sending data, but I suspect that delegate method never gets called.
I have tried adding
[application cancelAllLocalNotifications]
to both
- (void)applicationDidEnterBackground:(UIApplication *)application
and
- (void)applicationWillResignActive:(UIApplication *)application
but still seem to have an issue, any ideas.
Thanks
You can use CBPerpheral::setNotifyValue:forCharacteristic: to start or stop getting notification from the said peripheral.
Another option is to use session backgrounding. For that you need to add the bluetooth-central backgrounding mode to the app's plist file. After that the app is going to receive the bluetooth communication events both in foreground and background and no notifications will be generated by iOS. If your app decides it needs a notfification, it can simply generate a local notification (tutorial).
I have an iphone app that has a 30second process that does some network IO. Basically, while the app is in the background, i want this process to run every hour (actually once a day, but if it fails i want it to re-run in an hours time).
With the background features of ios 4, is this possible? If so, how? What are the limitations that i'll come up against?
Thanks so much!
Take a look at Apple's documentation about running code in the background.
http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/BackgroundExecution/BackgroundExecution.html
There are few different ways of approaching backgrounded tasks. The only apps that can have fully backgrounded processes are "audio", "voip" and "location" apps, and this needs to be declared in the Info.plist.
If your app is not of this type, you'll probably find it difficult to do what you want easily. There are methods which allow you to keep your app alive in the background for a finite period of time (also at that link), but eventually your app will be shut down.
Local Notifications will only prompt the user to open the app - do you really want to have an alert pop-up on the phone every 30 seconds?
I was making some kind of similar research, have a look at this SO answer in case you didn't manage to find it before. Applications like DataMan or Data Usage must have some sort of periodic code execution in the background, so I'm not 100% convinced that what you're asking for is impossible..
I believe that Using Local notifications will help....
check following....
http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/IPhoneOSClientImp/IPhoneOSClientImp.html#//apple_ref/doc/uid/TP40008194-CH103-SW1
An application can create and schedule a local notification, and the operating system then delivers it at the schedule date and time. If it delivers it when the application is not active in the foreground, it displays an alert, badges the application icon, or plays a sound—whatever is specified in the UILocalNotification object. If the application is running in the foreground, there is no alert, badging, or sound; instead, the application:didReceiveLocalNotification: method is called if the delegate implements it.
The delegate can inspect the properties of the notification and, if the notification includes custom data in its userInfo dictionary, it can access that data and process it accordingly. On the other hand, if the local notification only badges the application icon, and the user in response launches the application, the application:didFinishLaunchingWithOptions: method is invoked, but no UILocalNotification object is included in the options dictionary.
I want to make a special calendar app, but I am afraid it's not possible to safely schedule an alert for an event.
For example: I set up an alert for an event which starts in 3 months. I want to get notified 2 days before the event starts. In iOS 4 there is multitasking, so my app could run in the background all the time.
But now lets imagine it's a hardcore iPhone user who plays huge memory-intensive games all the time. At some point, iOS might kill my background app. Or the user might restart the device and forget to launch my app. So it could happen that the alert never happens. Bad thing.
Is there a safe way to ensure that an scheduled alert is thrown at the user, just like it is the case with the built in alarm clock app or the calendar app?
I'm going to bring back the EventKit notification - use event kit to schedule a calendar entry with an alert, and embed in there a URL that will open your app.
You could also use local notifications but this way the user will be able to see the upcoming event when reviewing the calendar, and even modify slightly if need be. They can't mess with a local notification once it's in place...
You want to use UILocalNotification for this.
EventKit will make it pop up in the user's calendar, maybe not what you want here.
BTW: Multitasking is really more "fast switching" than backgrounding in iOS... you won't be able to run arbitrary code in background, and you should expect to be killed anytime.