Question

在这里，我尝试使用协议将值从一个类LanguageSelectionTVC传递到另一个RegistrationVC。

当我尝试在self.delegate?.setSelectedLangauges(self.languagesSpokenArray)内调用方法LanguageSelectionTVC时，它不会调用类setSelectedLangauges中的方法Registration VC，有人可以建议我在哪里出错了？

protocol LanguageSelectionTVCProtocol {
    func setSelectedLangauges(_ valueSent: [String])
}


class LanguageSelectionTVC: UITableViewController {
    var delegate                    : LanguageSelectionTVCProtocol? = nil

   func saveAndClose() {
        self.delegate?.setSelectedLangauges(self.languagesSpokenArray)
        dismiss()
   }

}


class RegistrationVC:           UIViewController,
                                UITableViewDelegate,
                                UITableViewDataSource,
                                LanguageSelectionTVCProtocol{

    func setSelectedLangauges(_ valueSent: [String]){  
         self.showLanguagesSpoken(valueSent)
    }
}

从LanguageSelectionTVC移至RegistrationVC。以下tableView方法位于我的RegistrationVC

中

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let row     = indexPath.row
        let section = indexPath.section

        let currentCell = tableView.cellForRow(at: indexPath) as! UITableViewCell
        if section == 4 && row == 0 {
            // The user has clicked on languages spoken cell
            self.performSegue(withIdentifier: "LanguageSelectionTVC", sender: self)
        }
    }

Answer 1

您需要从preparForSegue访问delegate以设置override。因此prepare(for:sender:)中RegistrationVC override func prepare(for segue: UIStoryboardSegue, sender: Any?) { if segue.identifier == "LanguageSelectionTVC" { let vc = segue.destination as! LanguageSelectionTVC vc.delegate = self } }。{/ p>

googleapis

Answer 2

您需要将RegistrationVC中的委托设置为LanguageSelectionTVC，例如您可以在执行segue时设置它：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    let targetVC = segue.destination as! LanguageSelectionTVC
    targetVC.delegate = self
}

Answer 3

您需要设置委托。你能不能看到下面两个视图控制器之间传递数据的准备例子。

import UIKit
protocol SenderViewControllerDelegate 
{
    func messageData(str1:NSString)
}
class tableViewController: UIViewController, UITableViewDelegate, 
UITableViewDataSource 
{
var delegate: tableViewController?
override func viewDidLoad() 
{
    super.viewDidLoad()
    self.delegate?.messageData(str1: “Hello world”)
}
}

接收以下控制器中的数据

import UIKit
class HomeViewController: UIViewController ,SenderViewControllerDelegate {
    override func viewDidLoad() {
    super.viewDidLoad()
     let objtableview = tableViewController(nibName: "tableViewController",bundle: nil)
        objtableview.delegate = self
        self.navigationController?.pushViewController(objtableview, animated: true)
    }
    func messageData(str1:NSString){
        print(str1)
    }
}

委托函数不被称为iOS Swift

3 个答案: