我遇到了最令人沮丧的错误。我正在我的应用程序中设置通知，并使用swift 4.2。我正在使用新语法。我设置的弹出式控制器如下
NotificationCenter.default.post(name: .saveFoodGroup, object: self)
dismiss(animated: true, completion: nil)
我创建了一个名为的NotificationCenterExtension.swift文件
extension Notification.Name {
static let saveFoodGroup = Notification.Name(rawValue: "saveFoodGroup")
}
在我的控制器中，我将观察者设置在.viewDidLoad()内，如下所示：
NotificationCenter.default.addObserver(
forName: .saveFoodGroup,
object: nil,
queue: OperationQueue.main ) {
(notification) in
let groupPopUp = notification.object as! ScalePopUpController
print(groupPopUp)
self.foodGroup = groupPopUp.textInput as? String
}
但在运行时，我不断收到这个错误：
unrecognised selector sent to instance 0x7fb9c7e23ef0'
经过一些搜索，我发现当#选择器设置不正确时，这是一个旧的ObjC错误。但由于我使用的是新语法，所以这应该不是问题。最后一条线索：当我将鼠标悬停在NotificatioCenter.default.post(name: .saveFoodGroup(调用中的.saveFoodGroup参数上时；我得到了这个神秘的暗示；expression produced error: error:
/var/folders/xj/f18tylg51kl33z6c6p2vh34r0000gn/T/expr15-a14342.swift:1:65:错误：使用未声明的类型"名称"`
有人能告诉我发生了什么吗？
完整错误消息：
2018-12-04 20:17:28.780056+0100 unFatMobile[47399:4108185] -[unFatMobile.ScalePopUpController onBtPRew:]: unrecognized selector sent to instance 0x7fb9c7e23ef0
2018-12-04 20:17:28.787522+0100 unFatMobile[47399:4108185] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[unFatMobile.ScalePopUpController onBtPRew:]: unrecognized selector sent to instance 0x7fb9c7e23ef0'
(
0 CoreFoundation 0x000000010c6b91bb __exceptionPreprocess + 331
1 libobjc.A.dylib 0x000000010a6d3735 objc_exception_throw + 48
2 CoreFoundation 0x000000010c6d7f44 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
3 UIKitCore 0x000000010f091b4a -[UIResponder doesNotRecognizeSelector:] + 287
4 CoreFoundation 0x000000010c6bded6 ___forwarding___ + 1446
5 CoreFoundation 0x000000010c6bfda8 _CF_forwarding_prep_0 + 120
6 UIKitCore 0x000000010f064ecb -[UIApplication sendAction:to:from:forEvent:] + 83
7 UIKitCore 0x000000010eaa00bd -[UIControl sendAction:to:forEvent:] + 67
8 UIKitCore 0x000000010eaa03da -[UIControl _sendActionsForEvents:withEvent:] + 450
9 UIKitCore 0x000000010ea9f31e -[UIControl touchesEnded:withEvent:] + 583
10 UIKitCore 0x000000010f0a00a4 -[UIWindow _sendTouchesForEvent:] + 2729
11 UIKitCore 0x000000010f0a17a0 -[UIWindow sendEvent:] + 4080
12 UIKitCore 0x000000010f07f394 -[UIApplication sendEvent:] + 352
13 UIKit 0x0000000127f0b183 -[UIApplicationAccessibility sendEvent:] + 85
14 UIKitCore 0x000000010f1545a9 __dispatchPreprocessedEventFromEventQueue + 3054
15 UIKitCore 0x000000010f1571cb __handleEventQueueInternal + 5948
16 CoreFoundation 0x000000010c61e721 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
17 CoreFoundation 0x000000010c61df93 __CFRunLoopDoSources0 + 243
18 CoreFoundation 0x000000010c61863f __CFRunLoopRun + 1263
19 CoreFoundation 0x000000010c617e11 CFRunLoopRunSpecific + 625
20 GraphicsServices 0x00000001147d41dd GSEventRunModal + 62
21 UIKitCore 0x000000010f06381d UIApplicationMain + 140
22 unFatMobile 0x0000000109d56f47 main + 71
23 libdyld.dylib 0x000000010db52575 start + 1
)
从发布通知的位置(可能是按钮操作(
-[unFatMobile.ScalePopUpController onBtPRew:]
有一个名为onBtPRew的操作方法，您将其链接到Ib，然后将其删除，这里的通知实现(selector&&@objc(与此崩溃无关，新的内联回调正在中工作
Note :当您复制IB内部的元素时，也会发生这种情况，所附的操作与它们一起复制，因此请确保断开不相关的操作