ios - 使用选择器使用未解析的标识符

Question

我一直收到此错误 Use of unresolved identofier 'rightBarButtonDidClick'。

我已经声明了rightBarButtonDidClick类，
但为什么它显示错误？
根据之前关于相同主题的帖子，我尝试了所有可能的解决方案
就像检查目标成员资格等等。没关系。
这是完整的代码

import UIKit
import RealmSwift

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    @objc func rightBarButtonDidClick() {
        let alertController = UIAlertController(title: "Logout", message: "", preferredStyle: .alert)
        alertController.addAction(UIAlertAction(title: "Yes, Logout", style: .destructive, handler: {
            alert -> Void in
            SyncUser.current?.logOut()
            self.navigationController?.setViewControllers([WelcomeViewController()], animated: true)
        }))
        alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        self.present(alertController, animated: true, completion: nil)
    }

}

class ItemsViewController: UIViewController {

    let realm: Realm
    let items: Results<Item>

    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        let syncConfig = SyncConfiguration(user: SyncUser.current!, realmURL: Constants.REALM_URL)
        self.realm = try! Realm(configuration: Realm.Configuration(syncConfiguration: syncConfig, objectTypes:[Item.self]))
        self.items = realm.objects(Item.self).sorted(byKeyPath: "timestamp", ascending: false)
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    override func viewDidLoad() {
        super.viewDidLoad()

        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(rightBarButtonDidClick))
    }

        // Do any additional setup after loading the view.
    }

我正在使用 Swift 4.2 Xcode 10.0

Answer 1

您需要将此方法 rightBarButtonDidClick 移动到 ItemsViewController 中。

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }
}

class ItemsViewController: UIViewController {

    let realm: Realm
    let items: Results<Item>

    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        let syncConfig = SyncConfiguration(user: SyncUser.current!, realmURL: Constants.REALM_URL)
        self.realm = try! Realm(configuration: Realm.Configuration(syncConfiguration: syncConfig, objectTypes:[Item.self]))
        self.items = realm.objects(Item.self).sorted(byKeyPath: "timestamp", ascending: false)
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    override func viewDidLoad() {
        super.viewDidLoad()

        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(rightBarButtonDidClick))
    }

    @objc func rightBarButtonDidClick() {
        let alertController = UIAlertController(title: "Logout", message: "", preferredStyle: .alert)
        alertController.addAction(UIAlertAction(title: "Yes, Logout", style: .destructive, handler: {
            alert -> Void in
            SyncUser.current?.logOut()
            self.navigationController?.setViewControllers([WelcomeViewController()], animated: true)
        }))
        alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        self.present(alertController, animated: true, completion: nil)
    }
 }