notificationCenter.postNotificationName（NotificationContactCreated，object：nil）致命错误

Question

我有这行代码在第一次成功运行时成功运行：

notificationCenter.postNotificationName(NotificationContactCreated, object: nil)

但是稍后当调用相同函数中的同一行时，我得到fatal error：

  

致命错误：在解包可选值时意外发现nil

然而，如果我设置了代码，则通知中心和NotificationContactCreated都已设置。

我绕圈子找不到原因......

任何帮助......请????

由于

这是通知中心：

  //
// notification center to be used across phone app
//
lazy var notificationCenter: NSNotificationCenter = {

    return NSNotificationCenter.defaultCenter()
}()

这里是调用它的函数：

 func updateAccount(firstName: String, lastName: String, emailAddress: String, companyName: String, isSelf: Bool) -> Void {

    // we are going to update the Contacts entity
    let fetchRequest = NSFetchRequest(entityName: entityNameContacts)

    // filter on first name + last name + email address
    fetchRequest.predicate = NSPredicate(format: "firstName == %@ && lastName == %@ && emailAddress == %@", firstName, lastName, emailAddress)

    do {

        // try to get an array of accounts based on filter, should only be one returned
        let contactsArray = try context.executeFetchRequest(fetchRequest) as? [Contacts]

        // if there is a record we just want to update it
        if contactsArray?.count > 0 {

            // grab the reading object
            let contact = contactsArray![0]

            // and update its data
            contact.firstName = firstName

            contact.lastName = lastName

            contact.emailAddress = emailAddress

            contact.companyName = companyName
        }
        else {

            // otherwise we need to insert a new record
            let newContact: Contacts =  NSEntityDescription.insertNewObjectForEntityForName(entityNameContacts, inManagedObjectContext: context) as! Contacts

            // and populate with new data
            newContact.firstName = firstName

            newContact.lastName = lastName

            newContact.emailAddress = emailAddress

            newContact.companyName = companyName

            newContact.isSelf = isSelf
        }

        // write amends
        saveContext()

        self.notificationCenter.postNotificationName(NotificationContactCreated, object: nil)

    } catch {

        print("func updateAccount(firstName: String, lastName: String, emailAddress: String, companyName: String, isSelf: Bool) -> Void !!!ERROR")
    }