Hello I'm trying to get the multitasking work properly, but unfortunately I'm kinda lost. My problem is when I re-enter the game, it takes several seconds for the game to come back and show the pause screen. My question is; is there any way to put some sort of loading screen until the game comes back, so I can at least indicate that its not frozen? I've never used Xcode directly. I'm using Unity 3d to build my game. I made a little bit of research and if I'm not mistaken I'm supposed to use "applicationDidEnterBackground" app delegate method. My question is How can I put a custom loading screen using that method in Xcode?
Thanks
In -applicationDidEnterBackground:, you're given the opportunity to "clean up" the UI before the screenshot is taken. Apple says you should remove "sensitive data" (the screenshots might be persisted to "disk"?), but it also lets you do other things. In one app, we hide the label on a countdown timer so it doesn't appear to jump when you switch back to the app.
To change the "loading screen", simply display a full-screen view over the other views and remove it in -applicationWillEnterForeground:. Alternatively, pause the game in the first place!
(Really, you should be pausing the game in -applicationWillResignActive: which happens when the user double-taps home or the user receives a SMS/notification. I'm pretty sure it's called when the app is backgrounded, too.)
Related
I have seen some apps where when you launch them for the first time after downloading (e.g. Chrome app on iPhone), it shows you a list of animated gestures on the screen, kind of giving you a tour of the app.
How do I build one something like that? And how does the app know to launch only for the first time after download and not since then? For the second question, I am guessing a "shown=TRUE" value can be saved inside a PList file and checking the value each time when the app finished launching. But I am more curious about the mechanism involved in creating a guided app tour.
You can use transparent and semi-transparent images with a UIImageView, so you can make up an image with arrows and notes and put over the whole screen. You could fade it out when the user taps.
To know if it's the first time running the app, you should use NSUserDefaults instead of a plist; it's much easier, and you should be app to find a quick tutorial on that fairly easily.
Also, you could check around on this site for controls like this one. I haven't used any of them myself, so I'm not sure how much they differ from a regular UIImageView. They look nice though.
In one of my apps when returning from background I get a non consistent behavior:
Sometimes I get the default.png and sometimes I get a snapshot of the last screen which the app was in.
In both cases it takes the UI a good second or two to respond again.
Therefore I would rather show the default.png rather then "unresponsive UI"
Is there a way to make the app display the default.png always until the app becomes active again?
Currently the "stupid" way to do it I thought about is by displaying some Modal view with the default.png and removing it on return to foreground.
Few Clarification:
I am doing this to avoid unresponsive UI.
I am using the default.png as it looks like loading and gives a better experience then unresponsive UI
The app has to run in background.
(And to whoever asked - no it is not closed when I sometimes return and see the default.png and not the last UI state - App loading from the start has a very different path and I'm sure of that)
Thanks in advance.
This is not a correct behavior and you may experiencing a bug. Basically as long as your app is in the background, when you launch it, you should not see the default.png, unless you remove it from background (double click on home button and delete that app).
For future people interested in this you can use the fact the last view in the app is used to be displayed when the app loads back.
You can display a VC as your moving to background which will represent some loading - hence achieving the desired behavior.
I've already seen a few other apps using the same behavior in cases operations are ran when coming back into the app.
Most probably, you are taking too long (performing too many calculations) in methods such as applicationWillEnterForeground:, applicationDidBecomeActive:, etc. As a simple test, try commenting out the code in these methods and see if the problem occurs again.
Simply set in your Info.plist the property "Application doesn't run in background" to YES. The app will never go in background and when the home button is pressed it will be simply terminated. So you're back to the pre-iOS4 behavior.
Note that when you see now the default image at start-up it is simply because your app has been terminated while it was in background. This is normal especially for apps that take a lot of memory and then don't free it enough before going in the background (I think the threshold for the OS is about 18MB but I'm not sure)
My application brings up a different view each time it is built in Xcode. This is exactly what I want it to do. However, if I simply press the back to menu button in the simulator and then reopen it the view does not change. I am changing the view by overwriting the viewDidLoad function in a Custom View Controller. Why is it that ViewDidLoad is not called every time I click on the icon? Will that mean that on a real iphone it also will not be?
Thanks,
Sam
When you press the menu button in the simulator (or the actual iPhone) the OS, basically, stops running your app. However, it doesn't necessarily terminate the app; if you reopen the app before the OS has decided to terminate it, you will find yourself in the same state you were before. Since the app isn't reloaded, viewDidLoad isn't called.
However, viewWillAppear should still be called each time, I believe, and this might be a better place to put your code that changes how things look. Edit: A quick test shows that this isn't the case. I'll poke around and see if I can find another notification mechanism.
I have used to loading a default image in my appication. So i have set to,
Sleep(3); in my delegate.m class.
But sometimes it will take more than 6 to 7 minutes. So i want to display the image 3 seconds only and then it goes to my appilcation based on my requirements.
Which one is best way to do that?
Sleep(3) or [NSThread sleepForTimeInterval:3.0] or something else;
And i must display the image 3 seconds only. Please explain me.
(Note: And I declared setter and getter methods only in my deleagte class.)
Please explain me.
As Rob noted, Apple strongly recommends against a splash screen unless it hides some necessary behind the scenes process (like loading game graphics.) It is so strongly discouraged that some people have claimed that their apps have been rejected for using an unnecessary splash screen.
The default.png doesn't exist to create a splash screen. Instead it exist to allow you to create the illusion that your initial view loads faster than it does. You supposed to use it to provide an image of your initial view so that the enduser can begin to cognitively orient themselves to the interface. By the time they have oriented themselves to the interface and moved their finger to touch the interface, it is live.
Why? Because iPhone apps are supposed be quick in, quick out. People don't sit down to use them at a desk like a desktop. People use then on the go. Sometimes they use them in the middle of a conversation.
I tell my clients to test out the usability of their apps (except for games) while walking, riding an exercise bike etc as well as in the middle of a face-to-face and phone conversation. In those circumstances, a three second pause is a big deal and very noticeable especially if the app is a practical app. Imagine if every time you opened the Contact app you had to pause three seconds to see an Apple splash screen. You would get peeved in a hurry.
The key thing here is that an unnecessary splash screen doesn't add any value for the user. It is a selfish act on the part of the software publisher to eat the end users time so that the publisher can build brand recognition for the sole benefit of the publisher. Wasting three seconds of the users time every time they use the app adds up in a hurry. (In my experience, it also makes the user perceive that the overall app is slow and clunky.)
However, if you do want to shoot yourself in the foot or if you have a client hell bent on a splash screen, you do it like this:
The splash screen appears until the first view loads so you delay the loading of the first view. In the app delegates applicationDidFinishLaunching: method, remove all the code that loads the first view into the window. Replace it with a NSTimer. Put the code to load the first view in the timer's fire method.
With that setup the app will display the default.png as it launches, when it gets to applicationDidFinishLaunching:it will appear to pause from the end users perspective because no view will appear to replace the default.png.
You should note that the standard launch time for an app is 3-5 seconds. So you may not have to do anything to show the splash screen for 3 seconds. It might happen automatically.
Apple strictly recommends against this (using sleep in this way), especially in the scenario of showing a splash screen.
The best thing to do is create a view that looks like your Default.png file, then have that be the first NIB.. you could then set an NSTimer to transition (with animation if you want) to your main view/window/controller.
Is it possible to override the default behavior (close app) of the Home Button? And if how do you do that?
well, there's a reasonable alt to the need to detect if the Home button was tapped. i'm currently working on just such a scenario.
my app allows user input (into UITextViews). a customer has asked for an "autosave" feature where, should they (accidentally) tap the Home button during data entry, could i still capture the data entered and save it.
my testing of the sequence of viewWillDisappear in the view that is collecting the data and applicationWillTerminate show viewWillDisappear getting called before applicationWillTerminate. now i fully appreciate that this is the architected sequence Apple intended, BUT this sequence also precludes setting a simple Boolean in applicationWillTerminate to let the particular viewWillDisappear know that it is disappearing specifically due to applicationWillTerminate.
so the issue still stands. how can a UIView detect that it is disappearing specifically as a result of the app terminating?
Even if it is possible, your app will probably not be approved by Apple.
Are you planning this feature for your own private App or do you want to distribute it later on?
The home button is probably the most critical button on the device on not a good idea to change