multitasking

Use of background/foreground methods in AppDelegate

由 筅森魡賤 提交于 2019-11-27 09:58:22
问题 I'm planning to implement multi-task in my app. I can see many methods here to do that in the AppDelegate like applicationWillResignActive , applicationDidEnterBackground , applicationWillEnterForeground , ... But.... I don't see the way they should be used, nor why they are not in the ViewControllers... Nor what they are here for. I mean : when the app enter in background, i don't know on which view my user is. And back, when the app comes into foreground, how would I know what to do and

Difference between multitasking, multithreading and multiprocessing?

由 你。 提交于 2019-11-27 09:01:54
问题 Whats the difference between multitasking, multiprogramming & multiprocessing This comes regularly for my university OS exams and I can't find a good answer. I know quite a bit about multitasking and multiprogramming, but need to confirm it. 回答1: Paraphrasing wikipedia: Multiprogramming - A computer running more than one program at a time (like running Excel and Firefox simultaneously) http://en.wikipedia.org/wiki/Multiprogramming Multiprocessing - A computer using more than one CPU at a time

Force app to close and run in background

由 匆匆过客 提交于 2019-11-27 08:14:42
问题 we have an app that has a specific purpose where an exit is required. After the exit a process needs to run in the background for a certain amount of time or until finished. We just need to know how to programmatically force the app to enter the background where processes can continue running. Any help on this would be great! Thanks in advance! UPDATE: We have confirmed that there does not seem to be a programmatic way to force the app to quit / enter background and continue running

Unable to create UIBackgroundModes key in Info.plist for iOS4

由 徘徊边缘 提交于 2019-11-27 04:24:07
问题 I have an audio application which works great for iPhone 3.1.x versions. I am trying to upgrade it to iOS4.0 to work in multitasking environment. When I try to create a new UIBackgroundModes key in info.plist , it ("Required Background Modes") doesn't show up in drop down list? I also upgraded the Xcode SDK to 3.2.3, Base SDK to 4.0, deployment target to 4.0 but still UIBackgroundModes ("Required Background Modes") won't show up in info.plist drop down list. I also created test project for 4

Max number of goroutines

由 心不动则不痛 提交于 2019-11-27 03:03:33
How many goroutines can I use painless? For example wikipedia says, in Erlang 20 million processes can be created without degrading performance. Update: I've just investigated in goroutines performance a little and got such a results: It looks like goroutine lifetime is more then calculating sqrt() 1000 times ( ~45µs for me ), the only limitation is memory Goroutine costs 4 — 4.5 KB If a goroutine is blocked, there is no cost involved other than: memory usage slower garbage-collection The costs (in terms of memory and average time to actually start executing a goroutine) are: Go 1.6.2 (April

How to handle socket connection's events when app is in background?

由 ╄→尐↘猪︶ㄣ 提交于 2019-11-27 02:57:38
问题 I want use the following function even when app is in background? - (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent { case NSStreamEventHasBytesAvailable: { NSLog(@"Event:NSStreamEventHasBytesAvailable"); if (theStream == _inputStream) { NSLog(@"NSStreamEventHasBytesAvailable: on Input Stream"); uint8_t buffer[1024]; int len; while ([_inputStream hasBytesAvailable]) { len = [_inputStream read:buffer maxLength:sizeof(buffer)]; if (len > 0) { NSString *output = [

How to tell when controller has resumed from background?

由 杀马特。学长 韩版系。学妹 提交于 2019-11-27 02:48:48
问题 So I want to support app switching in my upcoming iPhone app and I've implemented all the proper delegate methods in my application delegate. So when the user resumes the application, I can see their activity in the NSLog and all. However, how can I tell my app has resumed a controller? Is there a method I can put in my controller to tell me the app has resumed in said controller? Reason I ask is because my application handles its own URL schema, and I want to update the view depending on the

When an iOS application goes to the background, are lengthy tasks paused?

由 白昼怎懂夜的黑 提交于 2019-11-27 00:08:02
Yes, I know if I wish my app to be responsive to users' multitasking actions, such as switch to another app, I should deal with - (void)applicationWillResignActive:(UIApplication *)application - (void)applicationDidBecomeActive:(UIApplication *)application What if my app is doing a quite-long time consuming operation (like downloading a big file) and the user causes my app to enter the background? Will that operation automatically be suspended and resumed when the user comes back to my app? What exactly will happen behind the scene when my app enters the background or resumes in the foreground

Having application running above other app

由 北城以北 提交于 2019-11-26 22:37:43
问题 I want to make an activity that can be opened above ANY app. Normally, even when the activity is set as dialog, when you switch to my app, you see my app, and in the background you see the launcher: BUT, I want the app will go above any app like this: (made in photoshop): I did see this question Creating a system overlay window (always on top), but in ICS there is no functionallity to the layout. Furthermore, I want to give a dialog box from my app without minimizing the other app... 回答1:

How to respond to push notification view if app is already running in the background

由 一笑奈何 提交于 2019-11-26 22:30:28
问题 I have something fairly simple I want to do. I attach a custom piece of data to some push notifications that I handle in -(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions I look for the UIApplicationLaunchOptionsRemoteNotificationKey and hey presto there it is. That method only gets called if my app is being launched for the first time. How do I read that same key if my application is running in the background already when the
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