ios - swift 类中的 AWS 配置行导致线程 1 : EXC_BAD_INSTRUCTION

Question

我构建了一个允许用户与 AWS Lex 聊天机器人进行通信的应用程序，但现在的问题是，当用户点击按钮开始与机器人进行对话时，它会崩溃并给我一个线程 1: EXC_BAD_INSTRUCTION 此行错误:

让配置= AWSServiceConfiguration(区域:botRegion!，credentialsProvider:AWSIdentityManager.default().credentialsProvider)

我真的很想知道是什么导致它出现这样的行为，因为 Xcode 不会突出显示代码的任何重要部分。

对于感兴趣的人来说，下面是我的代码的完整内容。

import Foundation
import UIKit
import Photos
import JSQMessagesViewController
import AWSLex
import AWSMobileHubHelper

let ClientSenderId = "Client"
let ServerSenderId = "Server"

class JeevesChatViewController: JSQMessagesViewController, JSQMessagesComposerTextViewPasteDelegate {

// The name of the bot.
var botName: String?

// The bot region
var botRegion: AWSRegionType?

// The bot alias
var botAlias: String?

// The messages communicated between the client and the server
var messages: [JSQMessage]?

// The interaction kit client
var interactionKit: AWSLexInteractionKit?

// The session attributes
var sessionAttributes: [AnyHashable: Any]?

// Contents of outgoing image
var outgoingBubbleImageData: JSQMessagesBubbleImage?

// Contents of incoming image
var incomingBubbleImageData: JSQMessagesBubbleImage?

// Used to store task completion source of iteraction kit
var textModeSwitchingCompletion: AWSTaskCompletionSource<NSString>?

// The client image
var clientImage: JSQMessagesAvatarImage?

// The bot image
var serverImage: JSQMessagesAvatarImage?

override func viewDidLoad() {
    super.viewDidLoad()

    // Make the initial setup for the bot.
    // Error occurs here - fatal error: unexpectedly found nil while unwrapping an Optional value
    let configuration = AWSServiceConfiguration(region: botRegion!, credentialsProvider: AWSIdentityManager.default().credentialsProvider)

    // Setup interaction kit configuration
    let botConfig = AWSLexInteractionKitConfig.defaultInteractionKitConfig(withBotName:botName!, botAlias: botAlias!)

    // Disable automatic voice playback
    botConfig.autoPlayback = false

    // Register the interaction kit client
    AWSLexInteractionKit.register(with: configuration!, interactionKitConfiguration: botConfig, forKey: botName!)

    // Fetch and set the interaction kit client
    self.interactionKit = AWSLexInteractionKit.init(forKey: botName!)

    // Set the interaction kit delegate
    // Remove 'as? AWSLexInteractionDelegate' statement later
    self.interactionKit?.interactionDelegate = self

    // Setup JSQMessagesViewController configuration
    self.showLoadEarlierMessagesHeader = false

    // Initialise the avatars for client and server here.


    // Setup the default keyboard type.
    self.inputToolbar.contentView?.textView?.keyboardType = UIKeyboardType.default

    // Initialise the messages list
    self.messages = [JSQMessage]()

    // Set the colours for messages bubbles 
    let bubbleFactory = JSQMessagesBubbleImageFactory()
    self.outgoingBubbleImageData = bubbleFactory?.outgoingMessagesBubbleImage(with: UIColor.jsq_messageBubbleGreen())
    self.incomingBubbleImageData = bubbleFactory?.incomingMessagesBubbleImage(with: UIColor.jsq_messageBubbleBlue())

    self.inputToolbar.contentView?.leftBarButtonItem = nil

    self.senderDisplayName = "User"

    self.senderId = ClientSenderId
}

// MARK: - JSQMessagesViewController delegate methods

override func didPressSend(_ button: UIButton!, withMessageText text: String!, senderId: String!, senderDisplayName: String!, date: Date!) {
    let message = JSQMessage(senderId: senderId, senderDisplayName: senderDisplayName, date: date, text: text)
    self.messages?.append(message!)

    if let textModeSwitchingCompletion = textModeSwitchingCompletion {
        textModeSwitchingCompletion.set(result: text as NSString)
        self.textModeSwitchingCompletion = nil
    }
    else {
        self.interactionKit?.text(inTextOut: text)
    }
    self.finishSendingMessage(animated: true)
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, messageDataForItemAt indexPath: IndexPath) -> JSQMessageData {

    return self.messages![indexPath.item]
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, didDeleteMessageAt indexPath: IndexPath) {
    // Nothing happens here
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, messageBubbleImageDataForItemAt indexPath: IndexPath) -> JSQMessageBubbleImageDataSource {

    let message = self.messages![indexPath.item]
    if (message.senderId == self.senderId) {
        return self.outgoingBubbleImageData!
    }
    return self.incomingBubbleImageData!
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, avatarImageDataForItemAt indexPath: IndexPath) -> JSQMessageAvatarImageDataSource? {

    let message = messages![indexPath.item]
    if message.senderId == ClientSenderId {
        return self.clientImage
    }
    return self.serverImage
}

override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    if let messages = messages {
        return messages.count
    }
    return 0
}

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = (super.collectionView(collectionView, cellForItemAt: indexPath) as! JSQMessagesCollectionViewCell)
    let msg = self.messages?[indexPath.item]
    if !msg!.isMediaMessage {
        if (msg?.senderId == self.senderId) {
            cell.textView?.textColor = UIColor.black
        }
        else {
            cell.textView?.textColor = UIColor.white
        }
    }
    return cell
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, attributedTextForCellTopLabelAt indexPath: IndexPath) -> NSAttributedString? {
    if indexPath.item % 3 == 0 {
        let message = self.messages?[indexPath.item]
        return JSQMessagesTimestampFormatter.shared().attributedTimestamp(for: message!.date)
    }
    return nil
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, attributedTextForMessageBubbleTopLabelAt indexPath: IndexPath) -> NSAttributedString? {
    let message = self.messages?[indexPath.item]

    // iOS 7 sender name labels
    if (message?.senderId == self.senderId) {
        return nil
    }

    if indexPath.item - 1 > 0 {
        let previousMessage = self.messages?[indexPath.item - 1]
        if (previousMessage?.senderId == message?.senderId) {
            return nil
        }
    }

    // Do not specify attributes to use the default values.
    return NSAttributedString(string: message!.senderDisplayName)
}

override func collectionView(_ collectionView: JSQMessagesCollectionView, attributedTextForCellBottomLabelAt indexPath: IndexPath) -> NSAttributedString? {
    return nil
}

func composerTextView(_ textView: JSQMessagesComposerTextView, shouldPasteWithSender sender: Any) -> Bool {
    return true
}

}

 // MARK: - Bot Interaction Kit
 extension JeevesChatViewController: AWSLexInteractionDelegate {

func interactionKit(_ interactionKit: AWSLexInteractionKit, onError error: Error) {
    print("Error occurred: \(error)")
}

func interactionKit(_ interactionKit: AWSLexInteractionKit, switchModeInput: AWSLexSwitchModeInput, completionSource: AWSTaskCompletionSource<AWSLexSwitchModeResponse>?) {
    self.sessionAttributes = switchModeInput.sessionAttributes
    DispatchQueue.main.async(execute: {
        let message: JSQMessage

        // Handle a successful transaction
        if (switchModeInput.dialogState == AWSLexDialogState.readyForFulfillment) {
            // Currently just displaying the slots return on ready for fulfillment
            if let slots = switchModeInput.slots {
                message = JSQMessage(senderId: ServerSenderId, senderDisplayName: "", date: Date(), text: "Slots:\n\(slots)")
                self.messages?.append(message)
                self.finishSendingMessage(animated: true)
            }
        } else {
                message = JSQMessage(senderId: ServerSenderId, senderDisplayName: "", date: Date(), text: switchModeInput.outputText!)
                self.messages?.append(message)
                self.finishSendingMessage(animated: true)
            }
    })
    // This can be expanded to take input from the user.
    let switchModeResponse  = AWSLexSwitchModeResponse()
    switchModeResponse.interactionMode = AWSLexInteractionMode.text
    switchModeResponse.sessionAttributes = switchModeInput.sessionAttributes
    completionSource?.set(result: switchModeResponse)

}

func interactionKitContinue(withText interactionKit: AWSLexInteractionKit, completionSource: AWSTaskCompletionSource<NSString>) {
    textModeSwitchingCompletion = completionSource
}
}

Answer 1

您没有正确设置您的credentialsProvider。AWSIdentityManager 从未初始化为被调用:

let configuration = AWSServiceConfiguration(region: botRegion!, credentialsProvider: AWSIdentityManager.default().credentialsProvider)

如果您将 AWS 用于 S3 存储桶，您应该使用隐身模式，因此

let cognitoIdentityPoolId = //"XYZ"
let cognitoUnauthRoleArn = //"XYZ"
let cognitoAuthRoleArn =  //"XYZ"
let credentialsProvider = AWSCognitoCredentialsProvider(regionType: #Wherever, identityPoolId: cognitoIdentityPoolId, unauthRoleArn: cognitoUnauthRoleArn, authRoleArn: cognitoAuthRoleArn, identityProviderManager: nil)

然后您可以将行更改为:

let configuration = AWSServiceConfiguration(region: botRegion!, credentialsProvider: credentialsProvider)