显示键盘时iOS App崩溃

Question

We have the following problem and this is how I reproduce it:

1. I have a textfield in the rootviewcontroller and in viewDidLoad I do:

    UITextField *tf = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 200, 200)]; tf.backgroundColor = [UIColor whiteColor]; tf.delegate = self; [self.view addSubview:tf]; [tf becomeFirstResponder]; 

2. The RootViewController has 2 containers, one for the side menu and one for the actual content-view. it DOES delegate UITextFieldDelegate and UITextViewDelegate

3. If we start the app the textfield behaves properly

4. After navigating through several view controllers like this:

    [destination.view setFrame:[[UIScreen mainScreen] applicationFrame]]; [self.currentVC willMoveToParentViewController:nil]; [self addChildViewController:destination]; [self transitionFromViewController:self.currentVC toViewController:destination duration:0.25 options:UIViewAnimationOptionTransitionCrossDissolve animations:nil completion:^(BOOL finished){ [self.currentVC removeFromParentViewController]; [destination didMoveToParentViewController:self]; self.currentVC = destination; self.currentSelection = selection; }]; 

whenever I want to display the Keyboard using “Cmd+K” (Simulator) I get an EXC_BAD_ACCESS

Again the ONLY way to get a crash is to display the system Keyboard

5. Enabling Zombies makes it a little bit better but it ends up crashing (ONLY if I open the keyboard).
6. I tried Malloc Guard but the VM runs out of memory and it doesn't really help

I'm out of ideas! Here is the trace:

0   0x00c1d160 in CALayerGetSuperlayer ()
1   0x00fae832 in -[UIView(Hierarchy) superview] ()
2   0x00fa144a in -[UIView nextResponder] ()
3   0x010f39f1 in -[UIResponder(Internal) _responderWindow] ()
4   0x00fbbc89 in -[UIView(Internal) _firstResponder] ()
5   0x010f25c2 in -[UIResponder isFirstResponder] ()
6   0x01748243 in -[UITextView _keyboardDidShow:] ()
7   0x0222d079 in __57-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke ()
8   0x02dd8be4 in __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ ()
9   0x02cc511b in _CFXNotificationPost ()
10  0x0221c5d6 in -[NSNotificationCenter postNotificationName:object:userInfo:] ()
11  0x016fe4e5 in -[UIInputWindowController postEndNotifications:withInfo:] ()
12  0x01705660 in -[UIInputWindowController keyboardHeightChangeDone] ()
13  0x0117da40 in -[UIKeyboardImpl _resizeForKeyplaneSize:splitWidthsChanged:] ()
14  0x012ebf42 in __66-[UIKeyboardPredictionView setPredictionViewState:animate:notify:]_block_invoke ()
15  0x00fb7c06 in +[UIView(UIViewAnimationWithBlocks) _setupAnimationWithDuration:delay:view:options:factory:animations:start:animationStateGenerator:completion:] ()
16  0x00fb7fc7 in +[UIView(UIViewAnimationWithBlocks) animateWithDuration:delay:options:animations:completion:] ()
17  0x012ebd31 in -[UIKeyboardPredictionView setPredictionViewState:animate:notify:] ()
18  0x012eb78a in -[UIKeyboardPredictionView setPredictionViewState:animate:] ()
19  0x01193b1a in -[UIKeyboardImpl showKeyboard] ()
20  0x01195fb0 in -[UIKeyboardImpl toggleSoftwareKeyboard] ()
21  0x01196020 in -[UIKeyboardImpl ejectKeyDown] ()
22  0x00f32920 in -[UIApplication _physicalButtonsBegan:withEvent:] ()
23  0x0269a7cd in -[NSObject performSelector:withObject:withObject:] ()
24  0x010f1c94 in forwardTouchMethod ()
25  0x010f4226 in -[UIResponder(Internal) _physicalButtonsBegan:withEvent:] ()
26  0x0269a7cd in -[NSObject performSelector:withObject:withObject:] ()
27  0x010f1c94 in forwardTouchMethod ()
28  0x010f4226 in -[UIResponder(Internal) _physicalButtonsBegan:withEvent:] ()
29  0x0269a7cd in -[NSObject performSelector:withObject:withObject:] ()
30  0x010f1c94 in forwardTouchMethod ()
31  0x010f4226 in -[UIResponder(Internal) _physicalButtonsBegan:withEvent:] ()
32  0x0269a7cd in -[NSObject performSelector:withObject:withObject:] ()
33  0x010f1c94 in forwardTouchMethod ()
34  0x010f4226 in -[UIResponder(Internal) _physicalButtonsBegan:withEvent:] ()
35  0x0176f4d3 in -[UITextField _physicalButtonsBegan:withEvent:] ()
36  0x00f8732a in -[UIWindow _sendButtonsForEvent:] ()
37  0x00f878d8 in -[UIWindow sendEvent:] ()
38  0x00f45681 in -[UIApplication sendEvent:] ()
39  0x00f55ab8 in _UIApplicationHandleEventFromQueueEvent ()
40  0x00f292e7 in _UIApplicationHandleEventQueue ()
41  0x02d3006f in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ ()
42  0x02d25b7d in __CFRunLoopDoSources0 ()
43  0x02d250d8 in __CFRunLoopRun ()
44  0x02d24a5b in CFRunLoopRunSpecific ()
45  0x02d2488b in CFRunLoopRunInMode ()
46  0x058352c9 in GSEventRunModal ()
47  0x05835106 in GSEventRun ()
48  0x00f2d0b6 in UIApplicationMain ()
49  0x001cd8ba in main at main.m:14
50  0x03b4cac9 in start ()

Update: I contacted apple support to get help since I HAVE to get this one solved. My thought is that we are doing some bad memory management but the Profiler shows no Zombies. We have one memory leak though in ADBEncondingStringToHex but were unable to do anything with that info. Maybe completely unrelated, maybe not...

Answer 1

I think calling [tf becomeFirstResponder] in viewDidLoad is too early - before the view is part of the app's view hierarchy. You should call it in viewWillAppear: or viewDidAppear: instead.

From the docs:

You may call this method to make a responder object such as a view the first responder. However, you should only call it on that view if it is part of a view hierarchy. If the view's window property holds a UIWindow object, it has been installed in a view hierarchy; if it returns nil, the view is detached from any hierarchy.

Answer 2

This kind of issue happened to me before in iOS8.xx (no problem with iOS7.xx though). I resolved it by calling resignFirstResponder of the textField that becomeFirstResponder before keyboard pop out. So I think you should call below code to resignFirstResponder of your tf textField before anything that bring out keyboard:

 [tf resignFirstResponder];