Question

我有login screen并且在成功登录后，我将对象详细信息通过navigation controller传递到侧栏menu controller（topView控制器）。在侧栏菜单中，我有两个选项，当从其他view controller切换到顶部view controller时，值将被删除（根据我的理解，我从loginVC传递值它可能没有持有这些价值观）。

截至目前，酒吧菜单转换工作正常。但是，当我从AnotherVC切换回HomeVC时，它不会保留从LoginVC传递的值。

有人可以帮我解决这个问题。

以下是我的代码段

故事板：

代码段：

On login button click: (LOGIN VC)

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "loginSuccessIdentifier" {
            if let navController = segue.destination as? UINavigationController {
            if let destinController = navController.topViewController as? HomeViewController {
                destinController.loggedInUser = sender as! UserDetails!
            }
            }
        }
    }

HOME VC：

var loggedInUser:UserDetails! //UserDetails class is defined separately. Contains variables like id,firstname, lastname etc. I'm displaying those values on HomeVC
 override func viewDidLoad() {
        super.viewDidLoad()

        addSlideMenuButton()

        tokenLbl.adjustsFontSizeToFitWidth = true
        nameLbl.adjustsFontSizeToFitWidth = true
        idLbl.adjustsFontSizeToFitWidth = true

        if(loggedInUser != nil)
        {
            firstLbl.text = loggedInUser.token
            secondLbl.text = loggedInUser.lastname
            idLbl.text = String(loggedInUser.agentId)
        }
    }

SIDEBARMENU VC：

protocol SlideMenuDelegate {
    func slideMenuItemSelectedAtIndex(_ index : Int32)
}

class MenuViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet var tblMenuOptions : UITableView!
    @IBOutlet var btnCloseMenuOverlay : UIButton!
    var arrayMenuOptions = [Dictionary<String,String>]()
    var btnMenu : UIButton!
    var delegate : SlideMenuDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
        tblMenuOptions.tableFooterView = UIView()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        updateArrayMenuOptions()
    }

    func updateArrayMenuOptions(){
        arrayMenuOptions.append(["title":"HOME VC", "icon":"Icon1"])
        arrayMenuOptions.append(["title":"ANOTHER VC", "icon":"Icon2"])

        tblMenuOptions.reloadData()
    }

    @IBAction func onCloseMenuClick(_ button:UIButton!){
        btnMenu.tag = 0

        if (self.delegate != nil) {
            var index = Int32(button.tag)
            if(button == self.btnCloseMenuOverlay){
                index = -1
            }
            delegate?.slideMenuItemSelectedAtIndex(index)
        }

        UIView.animate(withDuration: 0.3, animations: { () -> Void in
            self.view.frame = CGRect(x: -UIScreen.main.bounds.size.width, y: 0, width: UIScreen.main.bounds.size.width,height: UIScreen.main.bounds.size.height)
            self.view.layoutIfNeeded()
            self.view.backgroundColor = UIColor.clear
            }, completion: { (finished) -> Void in
                self.view.removeFromSuperview()
                self.removeFromParentViewController()
        })
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell : UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "cellMenu")!

        cell.selectionStyle = UITableViewCellSelectionStyle.none
        cell.layoutMargins = UIEdgeInsets.zero
        cell.preservesSuperviewLayoutMargins = false
        cell.backgroundColor = UIColor.clear

        let lblTitle : UILabel = cell.contentView.viewWithTag(101) as! UILabel
        let imgIcon : UIImageView = cell.contentView.viewWithTag(100) as! UIImageView

        imgIcon.image = UIImage(named: arrayMenuOptions[indexPath.row]["icon"]!)
        lblTitle.text = arrayMenuOptions[indexPath.row]["title"]!

        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let btn = UIButton(type: UIButtonType.custom)
        btn.tag = indexPath.row
        self.onCloseMenuClick(btn)
    }

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

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1;
    }
}

BASE VC :(用于滑动代表）

class BaseViewController: UIViewController, SlideMenuDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func slideMenuItemSelectedAtIndex(_ index: Int32) {
        let topViewController : UIViewController = self.navigationController!.topViewController!
        print("View Controller is : \(topViewController) \n", terminator: "")
        switch(index){
        case 0:
            print("HomeVC\n", terminator: "")

            self.openViewControllerBasedOnIdentifier("HomeVC")

            break
        case 1:
            print("AnotherVC\n", terminator: "")

            self.openViewControllerBasedOnIdentifier("AnotherVC")

            break
        default:
            print("default\n", terminator: "")
        }
    }

    func openViewControllerBasedOnIdentifier(_ strIdentifier:String){
        let destViewController : UIViewController = self.storyboard!.instantiateViewController(withIdentifier: strIdentifier)

        let topViewController : UIViewController = self.navigationController!.topViewController!

        if (topViewController.restorationIdentifier! == destViewController.restorationIdentifier!){
            print("Same VC")
        } else {
            self.navigationController!.pushViewController(destViewController, animated: true)
        }
    }

    //to add slide option button
    func addSlideMenuButton(){
        let btnShowMenu = UIButton(type: UIButtonType.system)
        btnShowMenu.setImage(self.defaultMenuImage(), for: UIControlState())
        btnShowMenu.frame = CGRect(x: 0, y: 0, width: 25, height: 25)
        btnShowMenu.addTarget(self, action: #selector(BaseViewController.onSlideMenuButtonPressed(_:)), for: UIControlEvents.touchUpInside)
        let customBarItem = UIBarButtonItem(customView: btnShowMenu)
        self.navigationItem.leftBarButtonItem = customBarItem;
    }

    func defaultMenuImage() -> UIImage {
        var defaultMenuImage = UIImage()

        UIGraphicsBeginImageContextWithOptions(CGSize(width: 30, height: 22), false, 0.0)

        UIColor.black.setFill()
        UIBezierPath(rect: CGRect(x: 0, y: 3, width: 30, height: 1)).fill()
        UIBezierPath(rect: CGRect(x: 0, y: 10, width: 30, height: 1)).fill()
        UIBezierPath(rect: CGRect(x: 0, y: 17, width: 30, height: 1)).fill()

        UIColor.white.setFill()
        UIBezierPath(rect: CGRect(x: 0, y: 4, width: 30, height: 1)).fill()
        UIBezierPath(rect: CGRect(x: 0, y: 11,  width: 30, height: 1)).fill()
        UIBezierPath(rect: CGRect(x: 0, y: 18, width: 30, height: 1)).fill()

        defaultMenuImage = UIGraphicsGetImageFromCurrentImageContext()!

        UIGraphicsEndImageContext()

        return defaultMenuImage;
    }

    func onSlideMenuButtonPressed(_ sender : UIButton){
        if (sender.tag == 10)
        {
            // To Hide Menu If it already there
            self.slideMenuItemSelectedAtIndex(-1);

            sender.tag = 0;

            let viewMenuBack : UIView = view.subviews.last!

            UIView.animate(withDuration: 0.3, animations: { () -> Void in
                var frameMenu : CGRect = viewMenuBack.frame
                frameMenu.origin.x = -1 * UIScreen.main.bounds.size.width
                viewMenuBack.frame = frameMenu
                viewMenuBack.layoutIfNeeded()
                viewMenuBack.backgroundColor = UIColor.clear
                }, completion: { (finished) -> Void in
                    viewMenuBack.removeFromSuperview()
            })

            return
        }

        sender.isEnabled = false
        sender.tag = 10

        let menuVC : MenuViewController = self.storyboard!.instantiateViewController(withIdentifier: "MenuViewController") as! MenuViewController
        menuVC.btnMenu = sender
        menuVC.delegate = self
        self.view.addSubview(menuVC.view)
        self.addChildViewController(menuVC)
        menuVC.view.layoutIfNeeded()


        menuVC.view.frame=CGRect(x: 0 - UIScreen.main.bounds.size.width, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height);

        UIView.animate(withDuration: 0.3, animations: { () -> Void in
            menuVC.view.frame=CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height);
            sender.isEnabled = true
            }, completion:nil)
    }
}

Answer 1

对于您只想在单个会话期间保留的无害数据，您可以将其作为实例属性存储在App Delegate中。要读/写，您只需创建一个对AppDelegate的新引用

let appDelegate = UIApplication.shared.delegate as! AppDelegate

appDelegate.yourProperty = "saveStuff"

如果您希望数据保持不变，并且数据量不大，请尝试NSUserDefaults。您只需确保您的对象符合NSCoder协议。

https://developer.apple.com/reference/foundation/userdefaults

如果您希望数据保持不变，并且数据量不大，并且数据应该是安全的，则应使用钥匙串服务。

https://developer.apple.com/reference/security/1658642-keychain_services

Xcode（Swift 3.0） - 如何在侧栏菜单中切换控制器时保留值

1 个答案: