iOS應用崩潰顯示，當鍵盤

Question

我們有以下的問題，這是我如何重現它：

1. 我有一個文本框在RootViewController的和viewDidLoad中我做的：

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

2. RootViewController有2個容器，一個用於側邊菜單，另一個用於實際的內容視圖。它並委託UITextFieldDelegate和UITextViewDelegate

3. 如果我們啓動應用程序的文本框正常

4. 行爲通過幾個視圖控制器導航這樣的後：

   [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; 
            }]; 
   

每當我想用顯示鍵盤「Cmd + K」（模擬器）我得到一個EXC_BAD_ACCESS

再一次得到崩潰的唯一方法是顯示系統鍵盤

1. 啓用殭屍使它有點更好，但它最終崩潰（只有當我打開鍵盤）。
2. 我試着malloc的後衛，但虛擬機運行的內存，它並不能真正幫助

我出出主意！下面是跟蹤：

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() 

更新：我接觸蘋果的支持，以獲得幫助，因爲我一定要得到這個解決。我的想法是，我們正在做一些不好的內存管理，但Profiler不顯示殭屍。儘管在ADBEncondingStringToHex中有一個內存泄漏，但無法對該信息進行任何操作。也許完全不相關，也許不是......

Answer 1

我認爲在viewDidLoad中調用[tf becomeFirstResponder]爲時尚早 - 在視圖是應用視圖層次結構的一部分之前。您應該將其稱爲viewWillAppear:或viewDidAppear:。

從文檔：

您可能會調用該方法做出響應者的物體，如視圖中的第一響應者。但是，如果它是視圖層次結構的一部分，則只應在該視圖上調用它。如果視圖的window屬性包含一個UIWindow對象，則它已安裝在視圖層次結構中;如果它返回nil，則該視圖將從任何層次結構中分離出來。

Answer 2

這種問題發生在我以前在iOS8.xx（儘管iOS7.xx沒有問題）。我通過在鍵盤彈出之前調用resignFirstResponder來解決它的問題，即成爲第一個響應者。所以我覺得任何事情之前，你應該調用下面的代碼，你TF 文本框的resignFirstResponder帶出鍵盤：

[tf resignFirstResponder];