为什么 viewDidAppear 没有调用？

Question

import UIKit

import SwiftyDropbox

class NotesViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, NotesviewDelegate {

var userText:[String] = []

@IBOutlet weak var tableView: UITableView!

override func viewDidLoad() {
    super.viewDidLoad()

    print("View Did Load Notes view controller")
}

override func viewWillAppear(_ animated: Bool) {
    print("View will Appear")
    self.tabBarController?.navigationItem.title = "Notes"

    let sendButton = UIBarButtonItem(title: "New", style: .plain, target: self, action: #selector(goToNoteEditorViewController))

    self.tabBarController?.navigationItem.rightBarButtonItem = sendButton
    self.automaticallyAdjustsScrollViewInsets = false
}

override func viewDidAppear(_ animated: Bool) {

    print("View Did appear Notes view controller")
    didDoneButtonPressed()

}

func goToNoteEditorViewController() {

    let storyboard = UIStoryboard(name: "Main", bundle: nil)

    guard let vc = storyboard.instantiateViewController(withIdentifier:"NoteEditorViewID") as? NoteEditorViewController else{
        return
    }
    vc.delegate = self
    self.navigationController?.present(vc, animated: true, completion: nil)

}


public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{

    return userText.count
}


public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{

    let cell = UITableViewCell(style: UITableViewCellStyle.default, reuseIdentifier: "cell")
    cell.textLabel?.text = userText[indexPath.row]
    print("The cell is \(cell)")
    return (cell)
}

public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){

    let controller = UIStoryboard(name: "Main", bundle: nil)

    guard let viewController = controller.instantiateViewController(withIdentifier:"TextDisplayID") as? TextDisplayViewController else{
        return
    }

    let indexPath = tableView.indexPathForSelectedRow

    let currentCell = tableView.cellForRow(at: indexPath!)!

    let text = currentCell.textLabel!.text ?? ""
    print(currentCell.textLabel!.text ?? "")

    viewController.textTitle = text
    navigationController?.pushViewController(viewController, animated: true)
}

func didDoneButtonPressed() {

    let userDefaults = UserDefaults()

    if let dictionary = userDefaults.dictionary(forKey: "UserNotes"){
        if let dictionaryTexts = dictionary as? [String : String] {
            userText = [String](dictionaryTexts.keys)

            print("array values: \(userText)")
            self.tableView.reloadData()
        }
    }
}
}

在上面的程序中，viewDidAppear 在 execution.Can 时没有被调用，谁能解释为什么会这样？

Answer 1

你应该调用 super.viewWillAppear 和 super.viewDidAppear()

override func viewWillAppear(_ animated: Bool) {
  super.viewWillAppear(animated: animated)
  print("View will Appear")
  self.tabBarController?.navigationItem.title = "Notes"

  let sendButton = UIBarButtonItem(title: "New", style: .plain, target: self, action: #selector(goToNoteEditorViewController))

  self.tabBarController?.navigationItem.rightBarButtonItem = sendButton
  self.automaticallyAdjustsScrollViewInsets = false
}

还有

override func viewDidAppear(_ animated: Bool) {
  super.viewDidAppear(animated: animated)
  print("View Did appear Notes view controller")
  didDoneButtonPressed()

}

编辑

您似乎已经对 UITabBarController 进行了分类。在您的 TabBarController 中，您需要调用 super.viewWillAppear() 和 super.viewDidAppear

class YourCustomTabBarController : UITabBarController {
   override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
  }

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

为什么 viewDidAppear 没有调用？

why the viewDidAppear is not calling?

viewdidappear

ios

swift