I'm developing a word game for iphone. Now that IOS has multitasking, do I definitely have to save the game state when the game is interrupted?
Your app can be unloaded by iOS whenever it decides to do so. Low memory, the user forces the app to close, etc.
Yes, you should save your game state if you want to be able to reinstate it when the app launches from scratch.
You may want to look into three20's persistance
http://three20.info/showcase/persistence
Related
My app has to run for a long time (also) in the background, due to Location Services.
When a certain condition is met the app has to move to the foreground.
I was able to run my app in the background and bring it to the front manually.
Reading up on this issue I got confused on how to move my app to the foreground by code.
It has to be in an if statement but what to do from here?
No do not think this is possible. You will be able to spawn a UILocalNotification to show application state to the user, but it is my understanding that iOS prevents you from making your app take focus.
you can't do that without user interaction. You can present a UILocalNotification
-- you can't even be sure iOS leaves it running though!
on a jailbroken phone I guess it is possible
This is clearly not possible, as it would be a mess if any app could just take over control at any point in time. As mentioned, you have to post a notification, and then it is up to the user if he or she wants to launch the app. If you notification states a good reason why they should launch your app, they might very well do it :-) And remember, don't mix up the user's needs with your/your app's needs.
Is it possible to flash a flashlight in iPhone when application is background mode?
Please give some suitable suggestion.
Already given the answer similar of your this question, pls see this link at once
Iphone flashlight not working while app is in background
This is a normal behavior.
Apple's sandboxing will not allow you to keep the flash on while your app is in the background.
There is no workaround unless we are talking about a jailbroken app.
Edit:
Apple is very strict on it's system's APIs usage. Especially when it comes to:
- User privacy
- Battery life
- User experience
In the case of the flashlight, the last two items are relevant. Apple will not let an app drain the battery when not in the foreground and iOS users are used to the fact that flashlight, camera, microphone... are immediately disabled when going to the background (with an exception for the microphone in some background modes cases).
To answer the comment on your initial post, iOS controls your hardware. So since Apple decided they don't want the light to stay on when the user closes the app, iOS will just power off the flash when your app goes in the background. Your app has no authority to prevent it.
When in background your application doesn't work or get any messages from the system.
The only cases when this is allowed are:
navigation application
audio player
Internet telephony
Unless you are designing any of the above you can not flash the user with anything.
If you only want to notify the user about something, you can create a notifier that will pop a message in the users window even if your application is in the background or entirely off. the user can click the message and then he will be back to your application
My app is an audio player, so it keeps running in the background. But flashlight works only when it's in the Foreground. No flashlight from the background.
try AVCaptureDevice
AVCaptureDevice
I'd like to build a pedometer which runs in the background on iOS5 devices. I understand the Core Motion framework can be used to accomplish this, like Nike+ is doing with their pedometer app.
I've also heard that there are restrictions on when Core Motion can be used in the background, specifically the OReilly's iOS 5 book says, "In iOS5 Core Motion is legal while your app is running in the background. To take advantage of this your app would need to be running in the background for some other reason."
This seems strange to me. Does this mean I have to have an "excuse" to use Core Motion in the background?
Yes, in order to run your app in the background, your app has to be in one of a few blessed categories: music, location, VOIP.
EDIT:
You can find the docs here: https://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/CoreData/Articles/cdRelationships.html
Just make it location aware. Log the pedometer activity and the GPS location.
I wrote my first iPhone App, and managed to get it into the App store. I later discovered a bug that happens on a real device but not on my emulator. I have committed a fix (changed plist to prevent app running in background), but I don't really understand why it happened.
My App allows users to record a sound-byte, however while they are recording they can use the iPhone home button to move the app to the background, and then it can keep recording forever if they don't restart the phone or the app does not crash.
My impression from everything I have read, is that this should not happen as you have to ask for background audio specifically if you want to do this, but now it appears to me that you have to ask specifically to disable it.
Could anyone explain this to me?
The iOS App lifecycle is described in Apple's iOS App Programming Guide.
The App is given the opportunity to save data and otherwise stop things that don't need to be running, before being suspended. You can request extra time doing this by using beginBackgroundTaskWithExpirationHandler:.
If you want your app to stop doing its "normal thing" when it is put into the background then you need to detect the App state transition and stop it yourself.
From the Getting Started with Game Center doc
A player might have the same Game Center enabled game loaded on multiple devices. If your
app has reported progress on an achievement from one device, note that the same
achievement progress data will be provided by Game Center on other devices where the user
plays your game. However, other game state maintained by your app may not be in sync and
should be handled accordingly.
I'm relatively new to iOS development and about to begin researching how to sync local game state data (i.e. which levels the player has completed, which levels the player is currently on, etc.) between the different hardware (iPhone, iTouch, and iPad) running my game and I was hoping I could get some insight from the SO users on some good ways to do this. Do I need to build a web service for this? Can iTunes be used to sync this data? Is there an API specifically built for this?
Thanks for your wisdom!
I think using a web serivice and making a JSON post and request would be a good route.
One suggested method by Apple is to use the Application Preferences, which is backed up by iTunes when the user syncs the phone.
I use NSUserDefaults for this and and it works great!
iCloud is your ticket