swift - 如何从登录 View 加载选项卡栏 Controller - Swift

Question

所以我用 Parse 为登录用户创建了一个 View Controller 。当用户通过输入登录按钮登录时，选项卡栏 View Controller 加载。问题是，如果用户打开应用程序并且他已经登录，我不希望他在没有输入登录信息的情况下离开。我希望签名 View Controller 将他发送到选项卡栏 View Controller 。

最初的 View Controller 是Tab bar View Controller ，我尝试了很多方法来处理这个问题，但似乎没有什么好的。

等待您的所有想法。

Answer 1

可能有很多不同的方法可以实现这一点，但我过去处理这种情况的一种方法是创建一个自定义容器 ViewController。该 VC 没有自己的 UIView，而是将其他 ViewController 作为其“ View ”呈现。

这是一些 Apple documentation 的链接描述了创建这种类型的 Controller 。

此架构的好处之一是，我始终有一个范围内的 VC，它可以根据与其帐户状态相关的事件(未登录、达到离线限制、帐户暂停、首先-)采取措施重新路由我的用户。时间用户、注销等)。

编辑:示例容器 Controller

以下是如何实现自定义容器 Controller 的示例。我确信有一些更好的方法可以实现此处所示的一些功能，但希望这能给您一个良好的开端。

import UIKit

class ApplicationContainerController: UIViewController {
    //MARK: - View Controller Routing Properties
    private var _currentClientView:UIView? = nil
    private var _currentViewController: UIViewController? = nil


    //MARK: - Initialization
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    //MARK: - UIViewController Members
    override func viewDidLoad() {
        super.viewDidLoad()

    }

    override var shouldAutomaticallyForwardAppearanceMethods : Bool {
        return true
    }

    override func viewWillAppear(_ animated: Bool) {

        //Get the user and route to the appropriate VC
        let yourUserObject: AnyObject? = YourDataSource.TryToGetAUser()
        DispatchQueue.main.async {
            self.routeUser(yourUserObject)
        }

    }

    //MARK: - Your Custom Routing Logic
    func routeUser(_ yourUserObject: AnyObject?) {

        //make sure we have an existing user, or else we send them to login
        guard let user = yourUserObject
            else {
                self.displayContentController(YourLoginViewController())
                return
        }

        var destinationViewController:UIViewController

        //please use an enum or something (instead of strings) in your code
        switch user.signInStatus {
            case "loginActive":
                let mainMenuViewController = YourMainMenuViewController()
                mainMenuViewController.user = user
                destinationViewController = mainMenuViewController
            case "firstLogin":
                let firstLoginViewController = YourFirstLoginViewController()
                firstLoginViewController.user = user
                destinationViewController = firstLoginViewController
            case "giveUsMoney":
                let weWantMoneyViewController = YourOtherViewController()
                weWantMoneyViewController.user = user
                destinationViewController = weWantMoneyViewController
            default:
                //loginFailed or some other status we don't know how to handle
                destinationViewController = YourLoginViewController()
        }


        if let activeViewController = self._currentViewController,
            type(of: activeViewController) !== type(of: destinationViewController) {
            //we have an active viewController that is not the destination, cycle
            self.cycleFromCurrentViewControllerToViewController(destinationViewController)
        } else {
            //no active viewControllers
            self.displayContentController(destinationViewController)
        }


    }



    //MARK: - Custom Content Controller Routing Methods
    private func frameForContentController() -> CGRect {
        return self.view.frame
    }

    private func newViewStartFrame() -> CGRect {
        return CGRect(x: self.view.frame.origin.x,
                      y: self.view.frame.origin.y + self.view.frame.size.width,
                      width: self.view.frame.size.width,
                      height: self.view.frame.size.height)
    }

    private func oldViewEndFrame() -> CGRect {
        return CGRect(x: self.view.frame.origin.x,
                      y: self.view.frame.origin.y - self.view.frame.size.width,
                      width: self.view.frame.size.width,
                      height: self.view.frame.size.height)
    }


    /**
     Transitions viewControllers, adds-to/removes-from context, and animates views on/off screen.
     */
    private func cycleFromCurrentViewControllerToViewController(_ newViewController: UIViewController) {
        if let currentViewController = self._currentViewController {
            self.cycleFromViewController(currentViewController, toViewController: newViewController)
        }
    }

    private func cycleFromViewController(_ oldViewController:UIViewController, toViewController newViewController:UIViewController) {

        let endFrame = self.oldViewEndFrame()

        oldViewController.willMove(toParentViewController: nil)
        self.addChildViewController(newViewController)
        newViewController.view.frame = self.newViewStartFrame()

        self.transition(from: oldViewController, to: newViewController,
                        duration: 0.5,
                        options: [],
                        animations: { () -> Void in
                            newViewController.view.frame = oldViewController.view.frame
                            oldViewController.view.frame = endFrame
        }) { (finished:Bool) -> Void in
            self.hideContentController(oldViewController)
            self.displayContentController(newViewController)
        }
    }


    /**
        Adds a view controller to the hierarchy and displays its view
    */
    private func displayContentController(_ contentController: UIViewController) {
        self.addChildViewController(contentController)
        contentController.view.frame = self.frameForContentController()
        self._currentClientView = contentController.view
        self.view.addSubview(self._currentClientView!)
        self._currentViewController = contentController
        contentController.didMove(toParentViewController: self)

    }

    /**
     Removes a previously added view controller from the hierarchy
    */
    private func hideContentController(_ contentController: UIViewController) {
        contentController.willMove(toParentViewController: nil)
        if (self._currentViewController == contentController) {
            self._currentViewController = nil
        }
        contentController.view.removeFromSuperview()
        contentController.removeFromParentViewController()

    }

}