如何在导航 SWIFT Xcode 中使用 segue？

Question

我正在构建一个简单的字典应用程序。我已经让它在用户搜索或不搜索时在 UItableView 上显示单词。我正在努力为每个单词分配自己的定义，但是在为单词数组中的每个单词设置目标时遇到了麻烦。

这是我的 ViewController 类及其内容的一部分：

import UIKit
class ViewController: UIViewController {

@IBOutlet weak var searchBar: UISearchBar!
@IBOutlet weak var tableView: UITableView!

var wordSearch = [String]()
var wordArray: [String] = []
var searching = false

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    
    let url = Bundle.main.url(forResource: "zo_words", withExtension: "txt")! // file URL for file "words_alpha.txt"

    do {
        let string = try String(contentsOf: url, encoding: .utf8)
        wordArray = string.components(separatedBy: "\n")
    } catch {
        print(error)
    }
 }
}
extension ViewController: UITableViewDataSource, UITableViewDelegate {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if searching {
            return wordSearch.count
        } else {
            return wordArray.count
                }

这是我的 wordSearch 功能：

extension ViewController: UISearchBarDelegate {
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    wordSearch = wordArray.filter({$0.lowercased().prefix(searchText.count) == searchText.lowercased();})
    searching = true
    tableView.reloadData()
}

无法将“String”类型的值分配给“ViewController”类型 构建时在下面的函数中引发错误

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let destination = segue.destination as? DefinitionViewController {
        destination.word = wordArray[(tableView.indexPathForSelectedRow?.row)!] 

类定义视图控制器：

import UIKit

class DefinitionViewController: UIViewController {
    @IBOutlet weak var lbDefinition:
        UILabel!
    var word: ViewController?
    override func viewDidLoad() {
        super.viewDidLoad()
    
        lbDefinition.text = "\((word?.wordSearch)!)"
}

}

Answer 1

我认为它不适用，建议从ViewController 获取实例，但您可以使用以下方法轻松完成： 假设您的 viewController 中有 word，那么您必须执行以下操作：

   override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        guard tableView.indexPathForSelectedRow != nil  else {
            return
        }

        let selectedWord = wordArray[tableView.indexPathForSelectedRow!.row]

        let destination = segue.destination as! DefinitionViewController

        destination.word = selectedWord
    }

定义视图控制器：

import UIKit

class DefinitionViewController: UIViewController {
    @IBOutlet weak var lbDefinition:
        UILabel!
    var word: String?
    override func viewDidLoad() {
        super.viewDidLoad()
        guard word != nil else {return}
        lbDefinition.text = "\((word?.wordSearch)!)"
    }
}

Answer 2

class ViewController: UIViewController {
      static var wordSearch = [string]()
 }

class DefinitionViewController: UIViewController {
 @IBOutlet weak var lbDefinition:UILabel!
 override func viewDidLoad() {
   super.viewDidLoad()
   lbDefinition.text = "\(ViewController.wordSearch)"
 }
}