崩溃：com.apple.main-thread-应用程序在保护声明中随机崩溃

Question

我在实时应用中随机崩溃。它在警卫声明上崩溃。以下是代码段。我不明白为什么它会在警惕性上崩溃，而这种情况应该防范这种崩溃？

如何解决此问题或如何进行调查？

Crashlytics日志

Crashed: com.apple.main-thread
EXC_BREAKPOINT 0x0000000102419850

0  myApp                          0x102426f50 MessageVC.validateBeforeSend() + 101 (MessageVC.swift:101)
1  myApp                          0x1024272d8 @objc MessageVC.buttonTapped(_:) + 239 (MessageVC.swift:239)
2  UIKitCore                      0x1a6a8d9ac <redacted> + 96
3  UIKitCore                      0x1a64c3fbc <redacted> + 240
4  UIKitCore                      0x1a64c4320 <redacted> + 408
5  UIKitCore                      0x1a64c333c <redacted> + 520
6  UIKitCore                      0x1a6674a58 <redacted> + 7636
7  CoreFoundation                 0x1a2983e68 <redacted> + 32
8  CoreFoundation                 0x1a297ed54 <redacted> + 416
9  CoreFoundation                 0x1a297f320 <redacted> + 1308
10 CoreFoundation                 0x1a297eadc CFRunLoopRunSpecific + 464
11 GraphicsServices               0x1ac91f328 GSEventRunModal + 104
12 UIKitCore                      0x1a6a8c63c UIApplicationMain + 1936
13 myApp                          0x1023eb850 main + 21 (ProfileVC.swift:11)
14 libdyld.dylib                  0x1a2808360 <redacted> + 4

Model.swift

struct ProfileStatus: Decodable {
    var status: Bool?
    var error: String?
}

MessageVC.swift

var profileStatus: ProfileStatus!

func validate() -> Bool {

    guard let status = profileStatus.status else { // Line no. 101, Crash here
        return true
    }
    // Do something...
}

@IBAction func buttonTapped(_ sender: UIButton) {
    if validate() { // Line no. 239
        // Do something..
    }
}

ProfileVC.swift

class ProfileVC: UIViewController {
    @IBOutlet weak var textField: MyTextField! // Line no. 11
    // ....
}

Answer 1

紧急撞车原因解开

var profileStatus: ProfileStatus! // << here is the reason

所以您需要在其他代码中找到丢失所有权的地方，并且这仍然是一种好习惯

var profileStatus: ProfileStatus? // use optional and unwrap where needed conditonally

func validate() -> Bool {

    guard let status = profileStatus?.status else {