ios - Swift 5 - 导航页面

Question

我刚开始使用 Swift 5，必须更新我的应用程序。我用....

let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home")
self.present(vc, animated: true, completion: nil)

将用户从登录屏幕推送到主应用程序，但更新后的外观如下所示(iPhone 当前处于暗模式)...

一些问题。这个功能到底叫什么？我该如何去操纵它？假设我想删除它，因为现在如果用户在主应用程序中，他们可以向下滑动并返回到登录屏幕，这肯定会导致问题。

登录查看 Controller 代码

import UIKit
import Firebase
import RealmSwift

class StartViewController: UITableViewController, UITextFieldDelegate {

@IBOutlet weak var email: UITextField!
@IBOutlet weak var password: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()

    // Check if user is already logged-in so they don't have to sign-in again
    checkUserSignIn()

    // Setting textfield delegates so user can press enter and go to next textfield
    self.email.delegate = self
    self.password.delegate = self

    let uid = Auth.auth().currentUser?.uid
    print(uid)
    print("printing the uid here")

}

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

    // Add a background view to the table view
    let backgroundImage = UIImage(named: "startBackground")
    let imageView = UIImageView(image: backgroundImage)
    self.tableView.backgroundView = imageView
    imageView.contentMode = .scaleAspectFill
}

// Check if user is already signed-in, if so push to main app
func checkUserSignIn() {
    Auth.auth().addStateDidChangeListener({ (auth, user) in
        if (user != nil) {
            Database.database().reference().child("users").child((user?.uid)!).observeSingleEvent(of: .value, with: { snapshot in
                if snapshot.exists() {
                    print("user is logged in")
                    let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home")
                    vc.modalPresentationStyle = .overCurrentContext
                    self.present(vc, animated: true, completion: nil)
                }
            })
        }
    })
}

@IBAction func login(_ sender: Any) {
    if self.email.text == "" || self.password.text == "" {

        //Alert to tell the user that there was an error because they didn't fill anything in the textfields because they didn't fill anything in

        let alertController = UIAlertController(title: "Error", message: "Please enter an email and password.", preferredStyle: .alert)

        let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
        alertController.addAction(defaultAction)

        self.present(alertController, animated: true, completion: nil)

    } else {

        Auth.auth().signIn(withEmail: self.email.text!, password: self.password.text!) { (user, error) in

            if error == nil {
                //Print into the console if successfully logged in
                print("You have successfully logged in")

                // Proceed To App
                func prepare(for segue: UIStoryboardSegue, sender: Any?) {
                    if(segue.identifier == "home") {
                    } else {
                        print("Problem sending user into nature app")
                    }
                }

            } else {

                //Tells the user that there is an error and then gets firebase to tell them the error
                let alertController = UIAlertController(title: "Error", message: error?.localizedDescription, preferredStyle: .alert)

                let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
                alertController.addAction(defaultAction)

                self.present(alertController, animated: true, completion: nil)
            }
        }
    }
}

@IBAction func createAccount(_ sender: Any) {
    // Check user has entered text into fields
    guard let email = email.text, email != "",
        let password = password.text, password != ""

        else {
            // Throw alert message to user if fields are empty
            let alert = UIAlertController(title: "Registration Error", message: "Please make sure you filled in all of the boxes to complete registration!", preferredStyle: .alert)
            let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
            alert.addAction(okAction)
            present(alert, animated: true, completion: nil)

            return
    }

    // Register a new user on Firebase
    Auth.auth().createUser(withEmail: email, password: password, completion: { (user, error) in

        // Throw registration error / Account could already exist
        if let error = error {
            let alert = UIAlertController(title: "Registration Error", message: error.localizedDescription, preferredStyle: .alert)
            let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
            alert.addAction(okAction)
            self.present(alert, animated: true, completion: nil)
            return
        }

        guard let userID = user?.user.uid else {
            return
        }

        // Database reference
        let databaseRef = Database.database().reference()
        // Set user information to firebase data structure
        let userInfo = fireUsersData(email: email, profPicString: "", uid: userID)
        databaseRef.child("users").child(userID).updateChildValues(userInfo.getUserDictionary(), withCompletionBlock: { (err, databaseRef) in

            let UserToAdd = realmUserData()
            UserToAdd.email = email
            UserToAdd.uid = userID
            //UserToAdd.saveDataToRealm()

            if err != nil {
                // Throw error is problem completeting
                let alert = UIAlertController(title: "Error", message: (err?.localizedDescription)! as String, preferredStyle: .alert)
                alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
                self.present(alert, animated: true, completion: nil)
            }
        })
    })

    // Dismiss keyboard
    self.view.endEditing(true)

    // Proceed To App
    func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if(segue.identifier == "home") {
        } else {
            print("Problem sending user into nature app")
        }
    }
}
// END OF FILE
}

Answer 1

在展示你的 ViewController 之前给出这个选项:

let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home")
vc.modalPresentationStyle = .overCurrentContext
self.present(vc, animated: true, completion: nil)

要忽略 didFinishLaunchingWithOptions 中的暗模式样式，请这样写:

 if #available(iOS 13.0, *) {
      window?.overrideUserInterfaceStyle = .light
  }

更新:将当前代码替换为:

let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home") as! UITabBarController

UIApplication.shared.keyWindow?.rootViewController = vc