我有一个 UITextField 我在模式对话框中呈现。在触摸 UITextField 时，会显示 ABPeoplePicker（联系人选择器）（也是模态的）。如果我随后关闭 ABPeoplePicker 和最初呈现的模式对话框，然后将应用程序置于后台，我会在应用程序恢复时遇到 EXC_BAD_ACCESS 崩溃。
使用僵尸：
# Address Category Event Type RefCt Timestamp Size Responsible Library Responsible Caller
0 0xda96640 UITextField Malloc 1 00:05.995.892 336 UIKit UINibDecoderDecodeObjectForValue
1 0xda96640 UITextField Retain 2 00:05.996.496 0 UIKit -[UIRuntimeConnection initWithCoder:]
2 0xda96640 UITextField Retain 3 00:05.996.504 0 UIKit -[UIRuntimeConnection initWithCoder:]
3 0xda96640 UITextField Retain 4 00:05.998.852 0 UIKit UINibDecoderDecodeObjectForValue
4 0xda96640 UITextField Retain 5 00:05.998.870 0 UIKit -[UIView(Internal) _addSubview:positioned:relativeTo:]
5 0xda96640 UITextField Retain 6 00:06.010.519 0 UIKit -[UIRuntimeConnection initWithCoder:]
6 0xda96640 UITextField Retain 7 00:06.010.991 0 UIKit UINibDecoderDecodeObjectForValue
7 0xda96640 UITextField Release 6 00:06.011.441 0 UIKit -[UINibDecoder finishDecoding]
8 0xda96640 UITextField Release 5 00:06.011.489 0 UIKit -[UINibDecoder finishDecoding]
9 0xda96640 UITextField Release 4 00:06.011.532 0 UIKit -[UINibDecoder finishDecoding]
10 0xda96640 UITextField Release 3 00:06.011.581 0 UIKit -[UIRuntimeConnection dealloc]
11 0xda96640 UITextField Release 2 00:06.011.659 0 UIKit -[UIRuntimeConnection dealloc]
12 0xda96640 UITextField Release 1 00:06.011.718 0 UIKit -[UIRuntimeConnection dealloc]
13 0xda96640 UITextField Retain 2 00:06.060.566 0 UIKit -[UIView _tryRetain]
14 0xda96640 UITextField Autorelease 00:06.060.567 0 MyApp -[MDDueViewController customerField]
15 0xda96640 UITextField Retain 3 00:06.060.567 0 MyApp -[MDDueViewController refreshView]
16 0xda96640 UITextField Release 2 00:06.060.569 0 MyApp -[MDDueViewController refreshView]
17 0xda96640 UITextField Retain 3 00:06.060.574 0 UIKit -[UIView _tryRetain]
18 0xda96640 UITextField Autorelease 00:06.060.575 0 MyApp -[MDDueViewController customerField]
19 0xda96640 UITextField Retain 4 00:06.060.575 0 MyApp -[MDDueViewController refreshView]
20 0xda96640 UITextField Release 3 00:06.060.669 0 MyApp -[MDDueViewController refreshView]
21 0xda96640 UITextField Retain 4 00:06.060.961 0 UIKit -[UIView _tryRetain]
22 0xda96640 UITextField Autorelease 00:06.060.962 0 MyApp -[MDDueViewController customerField]
23 0xda96640 UITextField Retain 5 00:06.060.962 0 MyApp -[MDDueViewController refreshView]
24 0xda96640 UITextField Release 4 00:06.060.963 0 MyApp -[MDDueViewController refreshView]
25 0xda96640 UITextField Release 3 00:06.066.904 0 UIKit _UIApplicationHandleEvent
26 0xda96640 UITextField Release 2 00:06.066.954 0 UIKit _UIApplicationHandleEvent
27 0xda96640 UITextField Release 1 00:06.066.955 0 UIKit _UIApplicationHandleEvent
28 0xda96640 UITextField Retain 2 00:06.072.625 0 QuartzCore -[CALayer layoutSublayers]
29 0xda96640 UITextField Release 1 00:06.072.809 0 QuartzCore -[CALayer layoutSublayers]
30 0xda96640 UITextField Retain 2 00:06.074.635 0 QuartzCore -[CALayer drawInContext:]
31 0xda96640 UITextField Release 1 00:06.074.645 0 QuartzCore -[CALayer drawInContext:]
32 0xda96640 UITextField Retain 2 00:07.399.074 0 UIKit -[UIView(Hierarchy) subviews]
33 0xda96640 UITextField Retain 3 00:07.960.376 0 UIKit -[UITouch(UITouchInternal) setView:]
34 0xda96640 UITextField Retain 4 00:07.960.377 0 UIKit -[UITouch(UITouchInternal) setGestureView:]
35 0xda96640 UITextField Retain 5 00:07.960.398 0 UIKit -[UITouch view]
36 0xda96640 UITextField Autorelease 00:07.960.399 0 UIKit -[UITouch view]
37 0xda96640 UITextField Retain 6 00:07.960.435 0 UIKit -[UITouch view]
38 0xda96640 UITextField Autorelease 00:07.960.436 0 UIKit -[UITouch view]
39 0xda96640 UITextField Retain 7 00:07.960.445 0 UIKit -[UITouch view]
40 0xda96640 UITextField Autorelease 00:07.960.445 0 UIKit -[UITouch view]
41 0xda96640 UITextField Retain 8 00:07.960.451 0 UIKit -[UITouch view]
42 0xda96640 UITextField Autorelease 00:07.960.451 0 UIKit -[UITouch view]
43 0xda96640 UITextField Retain 9 00:07.960.460 0 UIKit -[UITouch view]
44 0xda96640 UITextField Autorelease 00:07.960.461 0 UIKit -[UITouch view]
45 0xda96640 UITextField Retain 10 00:07.960.466 0 UIKit -[UITouch view]
46 0xda96640 UITextField Autorelease 00:07.960.467 0 UIKit -[UITouch view]
47 0xda96640 UITextField Retain 11 00:07.960.473 0 UIKit -[UITouch view]
48 0xda96640 UITextField Autorelease 00:07.960.473 0 UIKit -[UITouch view]
49 0xda96640 UITextField Retain 12 00:07.960.483 0 UIKit -[UITouch view]
50 0xda96640 UITextField Autorelease 00:07.960.483 0 UIKit -[UITouch view]
51 0xda96640 UITextField Retain 13 00:07.960.541 0 UIKit -[UITouch view]
52 0xda96640 UITextField Autorelease 00:07.960.541 0 UIKit -[UITouch view]
53 0xda96640 UITextField Retain 14 00:07.960.846 0 UIKit -[UITouch view]
54 0xda96640 UITextField Autorelease 00:07.960.847 0 UIKit -[UITouch view]
55 0xda96640 UITextField Retain 15 00:07.961.119 0 UIKit -[UITouchesEvent _cloneEvent]
56 0xda96640 UITextField Retain 16 00:07.961.181 0 UIKit -[UITouch _loadStateFromTouch:]
57 0xda96640 UITextField Retain 17 00:07.961.210 0 UIKit -[UITouch view]
58 0xda96640 UITextField Autorelease 00:07.961.210 0 UIKit -[UITouch view]
59 0xda96640 UITextField Retain 18 00:07.961.212 0 UIKit -[UITouchesEvent _viewsForWindow:]
60 0xda96640 UITextField Retain 19 00:07.961.218 0 UIKit -[UITouch view]
61 0xda96640 UITextField Autorelease 00:07.961.218 0 UIKit -[UITouch view]
62 0xda96640 UITextField Release 18 00:07.961.221 0 UIKit _UIApplicationHandleEvent
63 0xda96640 UITextField Release 17 00:07.961.225 0 UIKit _UIApplicationHandleEvent
64 0xda96640 UITextField Release 16 00:07.961.226 0 UIKit _UIApplicationHandleEvent
65 0xda96640 UITextField Release 15 00:07.961.244 0 UIKit _UIApplicationHandleEvent
66 0xda96640 UITextField Release 14 00:07.961.260 0 UIKit _UIApplicationHandleEvent
67 0xda96640 UITextField Release 13 00:07.961.271 0 UIKit _UIApplicationHandleEvent
68 0xda96640 UITextField Release 12 00:07.961.278 0 UIKit _UIApplicationHandleEvent
69 0xda96640 UITextField Release 11 00:07.961.278 0 UIKit _UIApplicationHandleEvent
70 0xda96640 UITextField Release 10 00:07.961.279 0 UIKit _UIApplicationHandleEvent
71 0xda96640 UITextField Release 9 00:07.961.279 0 UIKit _UIApplicationHandleEvent
72 0xda96640 UITextField Release 8 00:07.961.279 0 UIKit _UIApplicationHandleEvent
73 0xda96640 UITextField Release 7 00:07.961.280 0 UIKit _UIApplicationHandleEvent
74 0xda96640 UITextField Release 6 00:07.961.280 0 UIKit _UIApplicationHandleEvent
75 0xda96640 UITextField Release 5 00:07.961.286 0 UIKit _UIApplicationHandleEvent
76 0xda96640 UITextField Retain 6 00:07.961.311 0 QuartzCore -[CALayer layoutSublayers]
77 0xda96640 UITextField Release 5 00:07.961.403 0 QuartzCore -[CALayer layoutSublayers]
78 0xda96640 UITextField Retain 6 00:08.038.720 0 UIKit -[UITouch view]
79 0xda96640 UITextField Autorelease 00:08.038.721 0 UIKit -[UITouch view]
80 0xda96640 UITextField Retain 7 00:08.039.129 0 UIKit -[UITouch view]
81 0xda96640 UITextField Autorelease 00:08.039.130 0 UIKit -[UITouch view]
82 0xda96640 UITextField Retain 8 00:08.039.422 0 UIKit -[UITouch view]
83 0xda96640 UITextField Autorelease 00:08.039.422 0 UIKit -[UITouch view]
84 0xda96640 UITextField Retain 9 00:08.039.425 0 UIKit -[UITouch view]
85 0xda96640 UITextField Autorelease 00:08.039.426 0 UIKit -[UITouch view]
86 0xda96640 UITextField Retain 10 00:08.039.428 0 UIKit -[UIGestureRecognizer _shouldBegin]
87 0xda96640 UITextField Release 9 00:08.039.435 0 UIKit -[UIGestureRecognizer _shouldBegin]
88 0xda96640 UITextField Retain 10 00:08.039.644 0 UIKit -[UITouchesEvent _cloneEvent]
89 0xda96640 UITextField Retain 11 00:08.039.744 0 UIKit -[UITouch _loadStateFromTouch:]
90 0xda96640 UITextField Retain 12 00:08.039.782 0 UIKit -[UIResponder becomeFirstResponder]
91 0xda96640 UITextField Retain 13 00:08.039.831 0 UIKit -[UIWindow _setFirstResponder:]
92 0xda96640 UITextField Retain 14 00:08.041.734 0 UIKit -[UIFieldEditor becomeFieldEditorForView:]
93 0xda96640 UITextField Retain 15 00:08.042.968 0 MyApp -[MDDueViewController customerBeginEditing:]
94 0xda96640 UITextField Retain 16 00:08.083.655 0 UIKit -[UIViewController presentViewController:withTransition:completion:]
95 0xda96640 UITextField Retain 17 00:08.095.495 0 UIKit -[UITextField _resignFirstResponder]
96 0xda96640 UITextField Autorelease 00:08.095.496 0 UIKit -[UITextField _resignFirstResponder]
97 0xda96640 UITextField Retain 18 00:08.095.796 0 UIKit -[UIView _tryRetain]
98 0xda96640 UITextField Autorelease 00:08.095.797 0 MyApp -[MDDueViewController customerField]
99 0xda96640 UITextField Retain 19 00:08.095.798 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
100 0xda96640 UITextField Retain 20 00:08.095.818 0 UIKit -[UIView _tryRetain]
101 0xda96640 UITextField Autorelease 00:08.095.819 0 MyApp -[MDDueViewController customerField]
102 0xda96640 UITextField Retain 21 00:08.095.820 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
103 0xda96640 UITextField Release 20 00:08.095.838 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
104 0xda96640 UITextField Release 19 00:08.095.839 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
105 0xda96640 UITextField Release 18 00:08.095.869 0 UIKit -[UIFieldEditor becomeFieldEditorForView:]
106 0xda96640 UITextField Retain 19 00:08.096.237 0 Foundation +[NSConcreteNotification newTempNotificationWithName:object:userInfo:]
107 0xda96640 UITextField Release 18 00:08.096.243 0 Foundation -[NSConcreteNotification dealloc]
108 0xda96640 UITextField Release 17 00:08.096.248 0 MyApp -[MDDueViewController customerBeginEditing:]
109 0xda96640 UITextField Retain 18 00:08.097.915 0 Foundation +[NSConcreteNotification newTempNotificationWithName:object:userInfo:]
110 0xda96640 UITextField Release 17 00:08.097.919 0 Foundation -[NSConcreteNotification dealloc]
111 0xda96640 UITextField Release 16 00:08.097.929 0 UIKit -[UIResponder becomeFirstResponder]
112 0xda96640 UITextField Retain 17 00:08.097.939 0 UIKit -[UITouch view]
113 0xda96640 UITextField Autorelease 00:08.097.939 0 UIKit -[UITouch view]
114 0xda96640 UITextField Retain 18 00:08.097.979 0 UIKit -[UITouch view]
115 0xda96640 UITextField Autorelease 00:08.097.980 0 UIKit -[UITouch view]
116 0xda96640 UITextField Retain 19 00:08.097.981 0 UIKit -[UITouch view]
117 0xda96640 UITextField Autorelease 00:08.097.981 0 UIKit -[UITouch view]
118 0xda96640 UITextField Retain 20 00:08.097.984 0 UIKit -[UITouch view]
119 0xda96640 UITextField Autorelease 00:08.097.985 0 UIKit -[UITouch view]
120 0xda96640 UITextField Retain 21 00:08.097.989 0 UIKit -[UIApplication _cancelTouches:withEvent:includingGestures:notificationBlock:]
121 0xda96640 UITextField Retain 22 00:08.098.003 0 UIKit __98-[UIApplication _cancelViewProcessingOfTouches:withEvent:sendingTouchesCancelledToViewsOfTouches:]_block_invoke_0
122 0xda96640 UITextField Retain 23 00:08.098.032 0 UIKit -[UIApplication _cancelTouches:withEvent:includingGestures:notificationBlock:]
123 0xda96640 UITextField Retain 24 00:08.098.049 0 UIKit -[UITouch view]
124 0xda96640 UITextField Autorelease 00:08.098.049 0 UIKit -[UITouch view]
125 0xda96640 UITextField Release 23 00:08.098.050 0 UIKit -[UITouch(UITouchInternal) setView:]
126 0xda96640 UITextField Release 22 00:08.098.051 0 UIKit -[UITouch(UITouchInternal) setGestureView:]
127 0xda96640 UITextField Release 21 00:08.098.070 0 UIKit -[UIApplication _cancelTouches:withEvent:includingGestures:notificationBlock:]
128 0xda96640 UITextField Release 20 00:08.098.415 0 UIKit _UIApplicationHandleEvent
129 0xda96640 UITextField Release 19 00:08.098.422 0 UIKit _UIApplicationHandleEvent
130 0xda96640 UITextField Release 18 00:08.098.427 0 UIKit _UIApplicationHandleEvent
131 0xda96640 UITextField Release 17 00:08.098.428 0 UIKit _UIApplicationHandleEvent
132 0xda96640 UITextField Release 16 00:08.098.429 0 UIKit _UIApplicationHandleEvent
133 0xda96640 UITextField Release 15 00:08.098.429 0 UIKit _UIApplicationHandleEvent
134 0xda96640 UITextField Release 14 00:08.098.445 0 UIKit _UIApplicationHandleEvent
135 0xda96640 UITextField Release 13 00:08.098.548 0 UIKit _UIApplicationHandleEvent
136 0xda96640 UITextField Release 12 00:08.098.552 0 UIKit _UIApplicationHandleEvent
137 0xda96640 UITextField Release 11 00:08.098.592 0 UIKit _UIApplicationHandleEvent
138 0xda96640 UITextField Release 10 00:08.099.264 0 UIKit _UIApplicationHandleEvent
139 0xda96640 UITextField Release 9 00:08.099.275 0 UIKit -[UITouch dealloc]
140 0xda96640 UITextField Release 8 00:08.099.356 0 UIKit _UIApplicationHandleEvent
141 0xda96640 UITextField Release 7 00:08.099.372 0 UIKit _UIApplicationHandleEvent
142 0xda96640 UITextField Release 6 00:08.099.373 0 UIKit _UIApplicationHandleEvent
143 0xda96640 UITextField Release 5 00:08.099.383 0 UIKit _UIApplicationHandleEvent
144 0xda96640 UITextField Release 4 00:08.099.385 0 UIKit -[UITouch dealloc]
145 0xda96640 UITextField Release 3 00:08.099.656 0 UIKit _UIApplicationHandleEvent
146 0xda96640 UITextField Retain 4 00:08.102.385 0 QuartzCore -[CALayer layoutSublayers]
147 0xda96640 UITextField Release 3 00:08.102.455 0 QuartzCore -[CALayer layoutSublayers]
148 0xda96640 UITextField Retain 4 00:10.762.824 0 UIKit -[UIView _tryRetain]
149 0xda96640 UITextField Autorelease 00:10.762.825 0 MyApp -[MDDueViewController customerField]
150 0xda96640 UITextField Retain 5 00:10.762.825 0 MyApp -[MDDueViewController refreshView]
151 0xda96640 UITextField Release 4 00:10.762.828 0 MyApp -[MDDueViewController refreshView]
152 0xda96640 UITextField Retain 5 00:10.762.833 0 UIKit -[UIView _tryRetain]
153 0xda96640 UITextField Autorelease 00:10.762.833 0 MyApp -[MDDueViewController customerField]
154 0xda96640 UITextField Retain 6 00:10.762.834 0 MyApp -[MDDueViewController refreshView]
155 0xda96640 UITextField Release 5 00:10.762.888 0 MyApp -[MDDueViewController refreshView]
156 0xda96640 UITextField Retain 6 00:10.763.054 0 UIKit -[UIView _tryRetain]
157 0xda96640 UITextField Autorelease 00:10.763.054 0 MyApp -[MDDueViewController customerField]
158 0xda96640 UITextField Retain 7 00:10.763.055 0 MyApp -[MDDueViewController refreshView]
159 0xda96640 UITextField Release 6 00:10.763.056 0 MyApp -[MDDueViewController refreshView]
160 0xda96640 UITextField Retain 7 00:10.768.666 0 UIKit -[UIResponder becomeFirstResponder]
161 0xda96640 UITextField Retain 8 00:10.768.678 0 UIKit -[UIWindow _setFirstResponder:]
162 0xda96640 UITextField Retain 9 00:10.768.753 0 UIKit -[UIFieldEditor becomeFieldEditorForView:]
163 0xda96640 UITextField Retain 10 00:10.769.010 0 MyApp -[MDDueViewController customerBeginEditing:]
164 0xda96640 UITextField Retain 11 00:10.796.341 0 UIKit -[UITextField _resignFirstResponder]
165 0xda96640 UITextField Autorelease 00:10.796.342 0 UIKit -[UITextField _resignFirstResponder]
166 0xda96640 UITextField Retain 12 00:10.796.506 0 UIKit -[UIView _tryRetain]
167 0xda96640 UITextField Autorelease 00:10.796.507 0 MyApp -[MDDueViewController customerField]
168 0xda96640 UITextField Retain 13 00:10.796.508 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
169 0xda96640 UITextField Retain 14 00:10.796.522 0 UIKit -[UIView _tryRetain]
170 0xda96640 UITextField Autorelease 00:10.796.523 0 MyApp -[MDDueViewController customerField]
171 0xda96640 UITextField Retain 15 00:10.796.524 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
172 0xda96640 UITextField Release 14 00:10.796.536 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
173 0xda96640 UITextField Release 13 00:10.796.537 0 MyApp -[MDDueViewController customerFieldDidEndEditing:]
174 0xda96640 UITextField Release 12 00:10.796.562 0 UIKit -[UIFieldEditor becomeFieldEditorForView:]
175 0xda96640 UITextField Retain 13 00:10.796.980 0 Foundation +[NSConcreteNotification newTempNotificationWithName:object:userInfo:]
176 0xda96640 UITextField Release 12 00:10.796.983 0 Foundation -[NSConcreteNotification dealloc]
177 0xda96640 UITextField Release 11 00:10.797.049 0 MyApp -[MDDueViewController customerBeginEditing:]
178 0xda96640 UITextField Retain 12 00:10.797.754 0 Foundation +[NSConcreteNotification newTempNotificationWithName:object:userInfo:]
179 0xda96640 UITextField Release 11 00:10.797.757 0 Foundation -[NSConcreteNotification dealloc]
180 0xda96640 UITextField Release 10 00:10.797.763 0 UIKit -[UIResponder becomeFirstResponder]
181 0xda96640 UITextField Release 9 00:10.797.944 0 UIKit -[UIViewController _dismissViewControllerWithTransition:from:completion:]
182 0xda96640 UITextField Release 8 00:10.798.036 0 UIKit _UIApplicationHandleEvent
183 0xda96640 UITextField Release 7 00:10.798.040 0 UIKit _UIApplicationHandleEvent
184 0xda96640 UITextField Release 6 00:10.798.051 0 UIKit _UIApplicationHandleEvent
185 0xda96640 UITextField Release 5 00:10.802.137 0 UIKit _UIApplicationHandleEvent
186 0xda96640 UITextField Release 4 00:10.802.827 0 UIKit _UIApplicationHandleEvent
187 0xda96640 UITextField Release 3 00:10.802.867 0 UIKit _UIApplicationHandleEvent
188 0xda96640 UITextField Release 2 00:10.802.868 0 UIKit _UIApplicationHandleEvent
189 0xda96640 UITextField Retain 3 00:10.803.307 0 QuartzCore -[CALayer layoutSublayers]
190 0xda96640 UITextField Release 2 00:10.803.419 0 QuartzCore -[CALayer layoutSublayers]
191 0xda96640 UITextField Retain 3 00:14.465.011 0 QuartzCore -[CALayer layoutSublayers]
192 0xda96640 UITextField Release 2 00:14.465.118 0 QuartzCore -[CALayer layoutSublayers]
193 0xda96640 UITextField Release 1 00:17.082.546 0 UIKit -[UIView(Internal) _invalidateSubviewCache]
194 0xda96640 UITextField Release 0 00:17.082.555 0 UIKit -[UIView(Hierarchy) removeFromSuperview]
195 0xda96640 UITextField Zombie -1 00:19.533.987 0 Foundation __57-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_0
我在这里没有做任何太花哨的事情。我只是将我的几个 ViewController 方法绑定到情节提要中的 UITextField 的“Editing Did Begin”和“Editing Did End”事件，以便呈现和关闭 ABPeoplePicker：
- (IBAction)customerBeginEditing:(id)sender {
ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init];
picker.peoplePickerDelegate = self;
// Display only a person's phone, email, and birthdate
NSArray *displayedItems = [NSArray arrayWithObjects:[NSNumber numberWithInt:kABPersonPhoneProperty],
[NSNumber numberWithInt:kABPersonEmailProperty], nil];
picker.displayedProperties = displayedItems;
// Show the picker
[self presentModalViewController:picker animated:YES];
[sender resignFirstResponder]; //dismiss the keyboard from under the contact picker
}
选择联系人后，会发生以下情况 (ABPeoplePickerNavigationControllerDelegate)：
- (BOOL)peoplePickerNavigationController:(ABPeoplePickerNavigationController *)peoplePicker shouldContinueAfterSelectingPerson:(ABRecordRef)person {
[self setCustomerFromSelectedPerson:person];
[self dismissModalViewControllerAnimated:YES];
return NO;
}
最后：
- (void)customerFieldDidEndEditing:(UITextField *)textField {
if (self.customerField.text != nil && self.customerField.text.length > 0) {
self.saveButton.enabled = YES;
} else {
self.saveButton.enabled = NO;
}
}
有趣的是，崩溃只发生在 iOS 6 中。iOS 5 运行良好。
iOS 内部是否有一些与通知相关的东西试图以某种方式向我的 UITextField 发送消息？我缺少一些潜在的清理任务？我在其他地方使用相同的技术没有问题，这真的让我很困惑。我什至尝试将原始文本字段移动到“推送”样式演示文稿（而不是模态），以排除由于嵌套的模态呈现对话框引起的任何问题。
请注意，我使用的是 ARC，并且 UITextField 在我的 ViewController 中被声明为弱引用。
任何见解都非常感谢！谢谢！
更新
好的，我发现了问题，但我不明白为什么会这样。我已将问题归结为在 customerBeginEditing 中对 [sender resignFirstResponder] 的调用。出于某种原因，此调用导致在应用程序恢复时调用 [NSNotificationCenter addObserver:selector:name:object:]（但仅当不再显示具有 UITextField 的页面时）。我可以通过修改我的代码来解决我的问题，以便根本不必调用 resignFirstResponder 但我仍然不明白 iOS5 和 iOS6 之间发生了什么变化导致了这个问题。有人有想法么？