如何从 table 个静态单元格更改按钮标题？

Question

我有 HomeViewController，它以模式方式连接到导航控制器，标识符为：pickSubjectAction

SubjectPickerTableViewController 是我选择主题的地方。这是我的代码

import UIKit


class SubjectPickerTableViewController: UITableViewController {

    var subjects:[String] = [
        "English",
        "Math",
        "Science",
        "Geology",
        "Physics",
        "History"]

    var selectedSubject:String? {
        didSet {
            if let subject = selectedSubject {
                selectedSubjectIndex = subjects.index(of: subject)!
            }
        }
    }
    var selectedSubjectIndex:Int?

    override func viewDidLoad() {
        super.viewDidLoad()


    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return subjects.count
    }


    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "SubCell", for: indexPath)
        cell.textLabel?.text = subjects[indexPath.row]

        if indexPath.row == selectedSubjectIndex {
            cell.accessoryType = .checkmark
        } else {
            cell.accessoryType = .none
        }
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)

        //Other row is selected - need to deselect it
        if let index = selectedSubjectIndex {
            let cell = tableView.cellForRow(at: IndexPath(row: index, section: 0))
            cell?.accessoryType = .none
        }

        selectedSubject = subjects[indexPath.row]

        //update the checkmark for the current row
        let cell = tableView.cellForRow(at: indexPath)
        cell?.accessoryType = .checkmark
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "saveSelectedSubject" {
            if let cell = sender as? UITableViewCell {
                let indexPath = tableView.indexPath(for: cell)
                if let index = indexPath?.row {
                    selectedSubject = subjects[index]
                }
            }
        }
    }
}

这也与标识符 segued: savedSelectedSubject.

Q1：如何从按钮切换到 tableview 控制器？我试过了但失败了 Q2：如何更改所选主题的按钮标题？

我的资源：https://www.raywenderlich.com/113394/storyboards-tutorial-in-ios-9-part-2

感谢任何帮助。谢谢

Answer 1

How can i segued from button to the tableview controller? I tried this but failed

当您以 Any 格式发送时，

performSegueWithIdentifier 需要 String 格式。调用此函数的正确方法是

self.performSegue(withIdentifier: "pickSubjectAction", sender: self)

How to changed the button titled from selected Subject?

我猜您想在 savedSelectedSubject segue 之后在控制器中反映所选主题。让 ViewController A 成为你 pushing/presenting 的那个，ViewController B 成为 pushed/presented 的那个。请按照以下步骤操作：

为此，您需要通过 segue.destination 属性从 prepare(for segue: UIStoryboardSegue, sender: Any?) 函数中获取 目标控制器 (B)。

在 B 中创建一个 public 变量，您可以在其中设置您选择的主题。使用那个属性你可以显示你选择的主题标题。

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
  let B = segue.destination
    // Assuming B's public var is named selectedSubject and is of String type
   if let subject = self.selectedSubject {
      B.selectedSubject = subject
    }
}

在控制器 B 中

override func viewWillAppear() {
  super.viewWillAppear()
  button.setTitle(self.selectedSubject, for: .normal)
}
// We already have the value of selectedSubject which we are using to set title for the button.

如何从 table 个静态单元格更改按钮标题？

How to change button title from table static cells?

xcode

ios

swift

swift3

ios10