I'm developing an app on iOS 7 with a desired feature is that
When I home button, app enter background, I will add an image to current UIWindow. So when app enter background, if user double home button on iOS 7, os will show a small screenshot of current view of my app, so user can see my added image. :) (I did it)
When user return my app by clicking app icon, I want to remove this image immediately. In this situation, "immediately" means that user can NOT see this image anymore, user just see his/her current view when app enter foreground. I try to place the code remove image on the beginning of applicationWillEnterForeground delegate, but I'm still able to see this image for a short time after it disappears.
I also try to set hidden, alpha property for this imageview first, then removeFromSuperview, but it not works.
Can anyone help me to remove it "immediately" as my desire.
That is done automatically for all applications, you don't need to do anything in you code.
I don't think that you can do it faster, it depends of device performance. Sorry man.
Like other says it is really tricky how iOS handles these events. I've been researching and depends on the memory state of the device to do it faster or not. Indeed, in iPhone 4 and 4S may not show the image that you added on applicationWillEnterForeground method.
If I were you I would solve it by adding a smooth fade out animation of that image when the app becomes active again. With [UIView animateWithDuration: animations:] it could be nicely done! :)
If I find out something else I'll answer here!
Related
I am developing a security application. I need to disable the multitasking snapshot from being taken by iOS. I have made a fix for this by adding a black screen over my application window, when application resigns active mode. This logic seems to work fine when I press home button. But when I lock the screen, the logic is not effective, since the snapshot is already taken before control comes to applicationWillResignActive method. I have verified this by downloading the container folder from devices tab. Is there any way to fix this?
Thanks in advance!
I want to animate a set of images in my Launch Screen, but I do not know how. I have seen some tutorials telling me to put code in the App Delegate (DidFinishLaunchingWithOptions) and nothing has worked.
Could someone help me animate my Launch Screen?
I am supposing that you do quite a bit of work on launch, and you do not want your user to stare at a static image while this work is going on. What you need to do is do the work in the background (using gcd). This way, the launch screen will be gone quickly. However, you are not ready of course: hence your need for animations. So what I do is add my own equivalent of the start screen on top of my first visible UIView, do my animations and then tear down my start up screen. If you want to see what I do in action, try it out with my App (The Opera Player)
Im implementing touch ID to "unlock" my app, and im not sure if ive run into an apple bug or something i need to handle myself. If i tap the Home button and minimize my app before evaluatePolicy can load the Touch ID prompt, it appears over the home screen.
![not enough reputation to display screenshot, so heres a link]https://www.dropbox.com/s/zrhc60lx87ze7mt/IMG_0016.PNG
Successful/failure/cancel evaluation of this policy does nothing, but when i re-enter the app and cancel it again, touchID seems to be disabled forever until i restart the phone.
Anyone else running into this issue or have an ideas?
P.S. Theres an open radar where errSecUserCanceled is never returned from a cancel button tap, so right now i fall into my errSecAuthFailed case, which could also be the cause.
Answer is no. It should not be be displayed, when minimized.
The problem is IMHO that the code segment is being called again from your app when it goes to the background. For example loadView , didLoad and so on.
Try moving the code, that calls the authentication somewhere else in the program (different method).
For example, if your code uses a textView to enter password, you can implement the authentication within keyboardWillShow or similar.
Hope it helps.
My app has a registration screen that is only presented once, and after registration is completed it is never shown again.
If my startup screen is a screenshot of the app then I would need to provide two screenshots and for the correct one to be initially displayed when the app launches.
Is this possible?
No, it is not currently possible. You cannot access the Default.png (or whatever you've named it instead) from your app to update it.
If it were me, I would set the startup screen to the one that is appropriate long term. You could also theoretically update your registration screen to be a bit closer to the look and feel of the main app screen, so it isn't so far off visually.
In my app I use iphone camera, but the process is very low when I open it; then I want to start the process when I shows a splashscreen.
The problem is that when splashscreen ends I don't want to show camera.
Then while I show splashscreen I want to start process of camera and quit it before splashscreen disappear. Is it possible?
First up, Apple specifically advise against using splash screens in their Human Interface Guidelines document. I don't know if your app would get rejected for it, but best not to try.
Second, it sounds like you need to optimise the startup of your application and probably the first view controller. To do this, you need to put off loading/initialising everything you can until it's actually needed (known as "lazy initialisation). All code in applicationDidFinishLaunching: in your app delegate and your view controller's init method, loadView, viewDidLoad, viewWillAppear, viewDidAppear should be reviewed for stuff that could be done later.