Question

您好我试图将didSelectRowAtIndexPath func中的变量传递给另一个视图控制器：

class MessagesViewController: UIViewController, UITableViewDelegate {

        @IBOutlet var messagesTableView: UITableView!
        @IBOutlet var invitesButton: UIButton!

        var messagesTableViewDataSource: MessagesTableViewDatasource = MessagesTableViewDatasource()

        override func viewDidLoad() {
            super.viewDidLoad()

            messagesTableView.dataSource = self.messagesTableViewDataSource

            self.navigationController?.navigationBar.backgroundColor = UIColor.whiteColor()
            self.navigationController?.navigationBar.translucent = false

            let titleView = NavTitleView.init(frame: CGRect(x: 0, y: 0, width: 122, height: 32))
            titleView.title = "Messages"
            self.navigationItem.titleView = titleView

        }

        func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
            let cell: MessageCell = tableView.cellForRowAtIndexPath(indexPath) as! MessageCell
            let viewController = storyboard?.instantiateViewControllerWithIdentifier("ConversationViewController") as! ConversationViewController
            viewController.conversationUUID = cell.conversationUUID
            viewController.conversationProfileImage = cell.senderProfileImage
        }

        @IBAction func invitesButtonWasPressed() {
            performSegueWithIdentifier("segueToInvites", sender: self)
        }

        override func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
        }
    }

这里是构建单元格的地方：

        class MessagesTableViewDatasource: NSObject, UITableViewDataSource {

        var messages: [InboundMessage] = []

        func createMessagesArray(message: InboundMessage) {
            self.messages.append(message)
        }

        func loadMessages() -> [InboundMessage] {
            if self.messages.count > 0 {
                return self.messages
            } else {
                InboundMessage.all { messages in
                    messages.forEach(self.createMessagesArray)
                }
                return self.messages
            }
        }

        func createTableViewFooter(tableView: UITableView) {

            let footer = UILabel(frame: CGRectMake(0, 0, tableView.bounds.size.width - 100, tableView.bounds.size.height))
            footer.text = "You have no more messages."
            footer.textAlignment = .Center
            footer.textColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25)
            footer.font = Style.smallFont
            footer.sizeToFit()
            tableView.tableFooterView = footer
        }

        func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
            loadMessages()
            createTableViewFooter(tableView)

            let dateFormatter = NSDateFormatter()
            dateFormatter.dateStyle = NSDateFormatterStyle.ShortStyle
            dateFormatter.timeStyle = NSDateFormatterStyle.ShortStyle

            let cell: MessageCell = tableView.dequeueReusableCellWithIdentifier("MessageCell") as! MessageCell
            cell.senderName.text = messages[indexPath.row].senderName
            cell.senderText.text = messages[indexPath.row].senderText
            cell.timeMessageReceived.text = dateFormatter.stringFromDate(messages[indexPath.row].timeAndDateMessageReceived)
            cell.conversationUUID = messages[indexPath.row].conversationUUID

            if (messages[indexPath.row].senderProfileImageName != nil) {
                cell.senderProfileImage!.image = UIImage(named: messages[indexPath.row].senderProfileImageName)
            }
            if (messages[indexPath.row].hasBeenRead == false) {
                cell.unOpenedImage!.image = UIImage(named: "RedDot")
            }

            return cell
        }

        func numberOfSectionsInTableView(tableView: UITableView) -> Int {
            loadMessages()
            if self.messages.count == 0 {
                let noMessagesLabel = UILabel(frame: CGRectMake(0, 0, tableView.bounds.size.width, tableView.bounds.size.height))
                noMessagesLabel.text = "You have no messages at the moment."
                noMessagesLabel.textAlignment = .Center
                noMessagesLabel.sizeToFit()
                tableView.backgroundView = noMessagesLabel
                tableView.separatorStyle = .None

                return 0
            }
            return 1
        }

        func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
            return 50
        }

        func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            return messages.count
        }

    }

但是当我回到我的视图控制器时，值为零，我不明白为什么。这是传递给它的视图控制器：

class ConversationViewController: UIViewController {

        @IBOutlet var conversationTableView: UITableView!

        var conversationTableViewDataSource: ConversationTableViewDataSource = ConversationTableViewDataSource()
        var conversationUUID: NSUUID!
        var conversationProfileImage: UIImageView!

        override func viewDidLoad() {
            super.viewDidLoad()

            conversationTableView.dataSource = self.conversationTableViewDataSource
            conversationTableViewDataSource.conversationUUID = self.conversationUUID
            conversationTableViewDataSource.conversationProfileImage = self.conversationProfileImage

            self.navigationController?.navigationBar.backgroundColor = UIColor.whiteColor()
            self.navigationController?.navigationBar.translucent = false

    //        let titleView = NavTitleView.init(frame: CGRect(x: 0, y: 0, width: 122, height: 32))
    //        titleView.title = "Messages"
    //        self.navigationItem.titleView = titleView

        }

        override func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
        }
    }

我敢肯定，我错过了一些简单的东西，但由于我对这一切都很陌生，所以我无法在谷歌搜索后找到它并且希望能有所了解。

由于

Answer 1

您需要在prepareForSegue

中使用prepareForSegue方法添加MessagesViewController方法

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if (segue.identifier == "segueToConversation") {
        let destVC = segue.destinationViewController as! ConversationViewController
        let cell = sender as! MessageCell
        destVC.conversationUUID = cell.conversationUUID
        destVC.passImage = cell.senderProfileImage.image
    }
}

注意：您无法直接将图片分配给UIImageView对象conversationProfileImage，因为它尚未初始化，因此在UIImage的实例上创建{ {1}}名称为ConversationViewController，如我在回答中所写，然后使用passImage中的图像对象将图像分配给viewDidLoad。

使用didSelectRowAtIndexPath时值不持久

1 个答案: