：无法识别的select器发送到键盘按键实例？
我在静态表视图中添加了一些textField和textView 。 代码很好，并在xcode 6.4 / ios 8上运行*。但它是抛出exception，我不能跟踪。 现在我正在debugging代码在xcode 7.2（swift2.2）
我试图把符号和突破点，但没有运气:(
以下是崩溃的堆栈跟踪，预先感谢您的宝贵帮助。
2015-12-14 16:07:07.989 TuteMate[3380:90711] -[NSNull length]: unrecognized selector sent to instance 0x10ccc6af0 从特殊的断点：
CoreFoundation`-[NSObject(NSObject) doesNotRecognizeSelector:]: -> 0x10504e3c0 <+0>: pushq %rbp 0x10504e3c1 <+1>: movq %rsp, %rbp 0x10504e3c4 <+4>: pushq %r15 0x10504e3c6 <+6>: pushq %r14 0x10504e3c8 <+8>: pushq %rbx 0x10504e3c9 <+9>: pushq %rax 0x10504e3ca <+10>: movq %rdx, %r14 0x10504e3cd <+13>: movq %rdi, %rbx 0x10504e3d0 <+16>: movq 0x216c79(%rip), %rsi ; "class" 0x10504e3d7 <+23>: callq *0x229e1b(%rip) ; (void *)0x000000010730b800: objc_msgSend 0x10504e3dd <+29>: movq %rax, %rdi 0x10504e3e0 <+32>: movq %rbx, %rsi 0x10504e3e3 <+35>: movq %r14, %rdx 0x10504e3e6 <+38>: callq 0x10504ed00 ; __CFFullMethodName 0x10504e3eb <+43>: movq %rax, %r14 0x10504e3ee <+46>: leaq 0x23fdeb(%rip), %r15 ; @"%@: unrecognized selector sent to instance %p" 0x10504e3f5 <+53>: movl $0x3, %edi 0x10504e3fa <+58>: xorl %eax, %eax 0x10504e3fc <+60>: movq %r15, %rsi 0x10504e3ff <+63>: movq %r14, %rdx 0x10504e402 <+66>: movq %rbx, %rcx 0x10504e405 <+69>: callq 0x104fe2560 ; CFLog 0x10504e40a <+74>: leaq 0x22b90f(%rip), %rax ; kCFAllocatorSystemDefault 0x10504e411 <+81>: movq (%rax), %rdi 0x10504e414 <+84>: xorl %esi, %esi 0x10504e416 <+86>: xorl %eax, %eax 0x10504e418 <+88>: movq %r15, %rdx 0x10504e41b <+91>: movq %r14, %rcx 0x10504e41e <+94>: movq %rbx, %r8 0x10504e421 <+97>: callq 0x104f35190 ; CFStringCreateWithFormat 0x10504e426 <+102>: movq %rax, %rdi 0x10504e429 <+105>: callq 0x104f33580 ; CFMakeCollectable 0x10504e42e <+110>: movq %rax, %rbx 0x10504e431 <+113>: movq %rbx, %rdi 0x10504e434 <+116>: nop 0x10504e435 <+117>: nopl (%rax) 0x10504e439 <+121>: leaq 0x225300(%rip), %rax ; __CFOASafe 0x10504e440 <+128>: cmpb $0x0, (%rax) 0x10504e443 <+131>: je 0x10504e459 ; <+153> 0x10504e445 <+133>: movl $0x3, %edi 0x10504e44a <+138>: xorl %edx, %edx 0x10504e44c <+140>: xorl %ecx, %ecx 0x10504e44e <+142>: xorl %r8d, %r8d 0x10504e451 <+145>: movq %rbx, %rsi 0x10504e454 <+148>: callq 0x10501b150 ; __CFRecordAllocationEvent 0x10504e459 <+153>: movq %rbx, %rdi 0x10504e45c <+156>: callq 0x1050a3696 ; symbol stub for: _objc_rootAutorelease 0x10504e461 <+161>: movq 0x218370(%rip), %rdi ; (void *)0x00000001052690d0: NSException 0x10504e468 <+168>: leaq 0x234fb1(%rip), %rcx ; NSInvalidArgumentException 0x10504e46f <+175>: movq (%rcx), %rdx 0x10504e472 <+178>: movq 0x216c4f(%rip), %rsi ; "exceptionWithName:reason:userInfo:" 0x10504e479 <+185>: xorl %r8d, %r8d 0x10504e47c <+188>: movq %rax, %rcx 0x10504e47f <+191>: callq *0x229d73(%rip) ; (void *)0x000000010730b800: objc_msgSend 0x10504e485 <+197>: movq %rax, %rdi 0x10504e488 <+200>: callq 0x1050a3738 ; symbol stub for: objc_exception_throw 0x10504e48d <+205>: nopl (%rax)
更新堆栈跟踪
2015-12-14 16:45:58.932 TuteMate[4000:109943] -[NSNull length]: unrecognized selector sent to instance 0x105b72af0 2015-12-14 16:46:02.651 TuteMate[4000:109943] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSNull length]: unrecognized selector sent to instance 0x105b72af0' *** First throw call stack: ( 0 CoreFoundation 0x000000010594de65 __exceptionPreprocess + 165 1 libobjc.A.dylib 0x0000000107bfddeb objc_exception_throw + 48 2 CoreFoundation 0x000000010595648d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205 3 CoreFoundation 0x00000001058a390a ___forwarding___ + 970 4 CoreFoundation 0x00000001058a34b8 _CF_forwarding_prep_0 + 120 5 CoreFoundation 0x0000000105825dfa CFStringCompareWithOptionsAndLocale + 202 6 Foundation 0x0000000106019e37 -[NSString compare:options:range:] + 29 7 UIKit 0x00000001069c4e6f -[UIPhysicalKeyboardEvent _matchesKeyCommand:] + 303 8 UIKit 0x00000001068e93fd -[UIResponder _keyCommandForEvent:target:] + 364 9 UIKit 0x00000001068e95b2 -[UIResponder _keyCommandForEvent:target:] + 801 10 UIKit 0x00000001068e95b2 -[UIResponder _keyCommandForEvent:target:] + 801 11 UIKit 0x00000001068e95b2 -[UIResponder _keyCommandForEvent:target:] + 801 12 UIKit 0x00000001068e95b2 -[UIResponder _keyCommandForEvent:target:] + 801 13 UIKit 0x00000001068e95b2 -[UIResponder _keyCommandForEvent:target:] + 801 14 UIKit 0x00000001068e95b2 -[UIResponder _keyCommandForEvent:target:] + 801 15 UIKit 0x00000001066fb91a -[UIApplication _handleKeyUIEvent:] + 948 16 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 17 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 18 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 19 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 20 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 21 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 22 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 23 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 24 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 25 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 26 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 27 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 28 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 29 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 30 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 31 UIKit 0x00000001068e9e53 -[UIResponder _handleKeyUIEvent:] + 79 32 UIKit 0x00000001066fb2cd -[UIApplication handleKeyUIEvent:] + 79 33 UIKit 0x0000000106991c83 -[UIKeyboardImpl _handleKeyEvent:executionContext:] + 66 34 UIKit 0x0000000106b91cde -[UIKeyboardLayoutStar completeRetestForTouchUp:timestamp:interval:executionContext:] + 3356 35 UIKit 0x00000001069a0bbd __28-[UIKeyboardLayout touchUp:]_block_invoke + 228 36 UIKit 0x00000001070ed724 -[UIKeyboardTaskQueue continueExecutionOnMainThread] + 332 37 UIKit 0x00000001069a0ace -[UIKeyboardLayout touchUp:] + 236 38 UIKit 0x00000001069a1614 -[UIKeyboardLayout touchesEnded:withEvent:] + 348 39 UIKit 0x000000010674b49b -[UIWindow _sendTouchesForEvent:] + 835 40 UIKit 0x000000010674c1d0 -[UIWindow sendEvent:] + 865 41 UIKit 0x00000001066fab66 -[UIApplication sendEvent:] + 263 42 UIKit 0x00000001066d4d97 _UIApplicationHandleEventQueue + 6844 43 CoreFoundation 0x0000000105879a31 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 44 CoreFoundation 0x000000010586f95c __CFRunLoopDoSources0 + 556 45 CoreFoundation 0x000000010586ee13 __CFRunLoopRun + 867 46 CoreFoundation 0x000000010586e828 CFRunLoopRunSpecific + 488 47 GraphicsServices 0x000000010c9daad2 GSEventRunModal + 161 48 UIKit 0x00000001066da610 UIApplicationMain + 171 49 TuteMate 0x000000010500128d main + 109 50 libdyld.dylib 0x000000010932c92d start + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException
更新没有其他viewWillAppeaer，didAppear …方法实施！
override func viewDidLoad() { super.viewDidLoad() title = "Profile Edit" }
和table viewDelegates是
override func numberOfSectionsInTableView(tableView: UITableView) -> Int { // #warning Potentially incomplete method implementation. // Return the number of sections. return 1 } override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int { // #warning Incomplete method implementation. // Return the number of rows in the section. return 3 } override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { let cell = super.tableView(tableView, cellForRowAtIndexPath: indexPath) return cell }
@dip：从你的评论看来，你需要学习一些非常重要的debugging，那就是： 你相信的一切都是错误的 。 当你说“我不存储空或任何类似的东西”，我们知道这是错误的。 而第二个最重要的规则是： 相信证据 。
证据是，作为NSString方法的消息“length：”被发送到[NSNull null]。 你正在存储的地方[NSNull null]你应该在哪里存储一个string。 debugging的第三条规则： 你做错了什么。 有没有神秘的gremlins试图让你不高兴，这是你的代码是错的。 所以找出你正在存储的地方[NSNull null]。 任何来自JSONparsing器的东西总是一个不错的select。
解决方法 ：
我的问题是由于我无意中单击了属性检查器中的“键盘命令”控件而引起的。
看看我的回应在这里： https : //stackoverflow.com/a/36187611/5006807
我希望它可以帮助….