Is it possible to animate my UiView after an interval to come at the top of a screen even if the app is in background. I have been able to achieve this while the app is in foreground by adding my uiview as a subview to UiWindow. I am running a background thread too which shows that i am coming into that function where my uiview gets added into UiWindow but nothing shows when the app is in background.
Is there any restriction on iOS level ?
From Apple docs: https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html#//apple_ref/doc/uid/TP40007072-CH4-SW8
Avoid updating your windows and views. Because your app’s windows and
views are not visible when your app is in the background, you should
avoid updating them. The exception is in cases where you need to
update the contents of a window prior to having a snapshot of your app
taken.
Related
Killing and relaunching iOS app, If I have View Controller A,B,C last visible View Controller was C. So now when I relaunch app i see View Controller C for 10 sec and then shows up Splash Screen. How can I avoid this.
Because of this first 10 sec User cant perform any event on app.
I think this is an operation system bug. But if you want to avoid this, you can try to add a splash screen image view before your app will go to background. You need to add your custom overlay view as subview to current window. Use this method to implement this feature: applicationDidEnterBackground. You can find more information about this feature here:
Display a view or splash screen before applicationDidEnterBackground (to avoid active view screenshot)
To force iOS to launch an app with its default viewcontroller or launch image, you need to call
UIApplication.shared.ignoreSnapshotOnNextApplicationLaunch()
where you implement state preservation.
Form the documentation : Documentation
Prevents the app from using the recent snapshot image during the next launch cycle.
My app can be launched via UIApplicationLaunchOptionsLocalNotificationKey in the background. In that case the usual flow to setup initail view controller and some animations on the app's landing-page/first-page of the app take place.
My question is, Is this a good practice, If I leave these animations like this even when my app is launched via OS in background? Three things I am concerned about:
Some animations are continuous, like a circular-dot(UIImage) expanding and shrinking, using CAAnimation.
Some views are added and removed as subviews to the keyWindow, based on user location.
When user taps the home button, do I need to stop the animations and subview additions then also?
Making the animation stop and resume via applicationDidEnterBackground and applicationWillEnterForeground seems tedious.
I develop an iOS Keyboard extension, and I'm using scroll gestures on keyboard. Sometimes when using the keyboard I scroll up the control center and my keyboard stops working fine. Is there any way to detect if control center become visible, or invisible?
You can't do it directly. The most you can know is that your app was deactivated and then activated again. It could be because of the control center, it could be because of the notification center, it could be because a phone call came in, it could be because the user went into the app switcher and came back again...
Here is the possible work around you can try:
It is the UIWindow subclass to enable behavior like adaptive round-corners & detecting when Control Center is opened. This UIWindow subclass does probably the thing you want. You simply subscribe to an NSNotification and can react to the user opening Control Center. Detailed instructions and setup on Github
https://github.com/aaronabentheuer/AAWindow
[AAWindow: The way this is accomplished is by using a combination of NSTimer and overwriting sendEvent in UIWindow to receive all touches without blocking them. So you basically receive all touches check if they are near the lower edge of the screen, if yes set a timer for a half a second and if during this timer is running applicationWillResignActive is called you can be almost certain that ControlCenter is opened. The time has to vary if there's no statusbar, because then the app is in fullscreen and it can take the user up to 3 seconds to launch Control Center.]
Hope it would help you figure out the exact solution to your problem.
I created an iOS 7 passcode replica and I have this problem I can't seem to solve. I need the lock screen view to be on top of everything else, so the app is covered in iOS' multitasking view, so I add it directly to the keyWindow. Everything fine so far.
The problem arises if there's an alertView or actionSheet (will only mention alertViews in this post, to keep it simple) open when I have to display the lock screen. It has been answered several times that there are no references to alertViews in iOS 7, which is true, and the window in which they are displayed is _UIModalItemHostingWindow, which has 2 UIViews, indeed with no reference to the alertView.
This _UIModalItemHostingWindow also becomes the new keyWindow, so it's on top of everything else, but it can not be found in [UIApplication sharedApplication].windows meaning if I add the lock screen to my former keyWindow (the default keyWindow, if you will), it will be beneath the alertView and its dimmed background, so the user can't interact with the lock screen before dismissing the alertView. The other option is detailed a bit further below.
The lock screen works like this: on applicationDidEnterBackground it checks if the passcode is enabled; if it is enabled and the passcode duration is 0 (user selected to lock the app immediately), it adds the lock screen now, so it covers the app in the multitasking view. Now, the option I mentioned above is to add the alertView to this _UIModalItemHostingWindow window, but when returning to the app, the lock screen view is displayed with a 1+ second delay (even though I added it before I went to background!) and the app isn't covered by anything in the multitasking view. (Currently it's displayed in the wrong position too, if you go ahead and download it, that is fixed, but I didn't pushed the commit yet).
I tried hiding and removeFromSuperview this _UIModalItemHostingWindow, but when coming back to the app, the alertView animation still runs as if it was just fired. I suspect the delay mentioned above also happens due to how Apple handles alertViews when coming back to foreground.
I also tried creating a new window and to make that the new keyWindow, but same thing happens.
Here's a small discussion about this, covering all the stuff I tried, maybe I missed something in this post.
https://github.com/rolandleth/LTHPasscodeViewController/issues/16
Any ideas? Except creating manual references to every alertView and actionSheet inside my app, because I'm trying to find a fix for the passcode library, not my own apps; I can find dirty workarounds for that, no problem :)
Update: The window is _UIAlertOverlayWindow if an actionSheet is used instead of an alertView, but it behaves the same as far as I can tell.
The simplest solution is to have a lockscreen window instead of a lockscreen view.
Create a new UIWindow, set its frame to UIScreen bounds, put a simple rootViewController there that should handle rotation and display your "lock screen" views and set the windowLevel to UIWindowLevelAlert + 1.
Then set window's hidden to YES. Whenewer you want to show the lockscreen, just set hidden to NO.
I guess that adding a view to keyWindow also doesn't work when a popover/action sheet is displayed and also when a keyboard is displayed (keyboard has its own window on top of the key window).
During an active VOIP call, my app is put into the background when an incoming cellular call is received and answered. If, while on the cellular call, I bring my app back to the foreground the app view appears but is unresponsive. The "Touch to return to call" banner appears at the top of the view in green but the app view appears as if there is a darker transparent window overlaid on top of it preventing the view from receiving input. If I put my app into the background, bring another app to the foreground and then bring my app back to the foreground everything works as expected so the problem seems to be specific to active cell calls and/or the green banner only? In Settings->Notifications->Phone I tried turning Notification Center OFF and Alert Style NONE in the hopes of removing the banner to see if the problem still exists but these settings do not effect that banner. In addtion to the App window appearing to have a transparent window overlaid on it, if I touch the window I'm able to drag the entire app window (or view) in all directions (up down side to side) and it has a bounce effect (like tableview vertical scroll) when I release it.
If I dont know the problem I cannot fix it (:
Thanks..
Are you sure there's no view being added on top your view which might be intercepting all your events? My second guess would've been that your app received a memory warning and unloaded a bunch of views. However, that's not very likely since you still see all the views.
I don't know what you really mean to "bring your app back to the foreground",but I can tell you for sure that you cannot call in the same thread the UI and the incoming call, so for situations like this when you want to render some view during a call you can try something like this:
public void InvokeGUIThread(Action action)
{
Dispatcher.Invoke(action);
}
For example if you want to set a text in a textblock do something like this:
InvokeGUIThread(() =>
{
textBlockSome.Text = e.Item.ToString();
});