Ios 如何将文本字段数据从第三个viewcontroller传递到第一个viewcontroller

我想将

ViewControllerC

中textfield中的文本发送到

ViewControllerA

通过使用代理，我试图将文本从

ViewControllerC

传递到

ViewControllerA

我无法在

ViewControllerC

有人能帮我吗

ViewControllerC

protocol DataEnteredInDestinationDelegate: class {
    func userDidEnterInformation(info: String)
}

class DestinationSearchViewController: MirroringViewController {

var delegate: DataEnteredInDestinationDelegate?

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

        let cell: UITableViewCell? = tableView.cellForRow(at: indexPath)
        componetsTextField.text = cell?.textLabel?.text

        delegate?.userDidEnterInformation()

        self.navigationController?.popToRootViewController(animated: true)
    }
}

ViewControllerA

class HomeViewController: MirroringViewController, DataEnteredInDestinationDelegate
{
    func userDidEnterInformation(info: String){
        locationView.destination.text = info
    }
}

此外，还应设置

ViewControllerC

的委托

viewControllerC.delegate = viewControllerA

---

首先，您必须始终将代表标记为弱，例如：

weak var delegate: DataEnteredInDestinationDelegate?

然后，您需要像这样连接代理：

let vcA = ViewControllerA() 
let vcC = ViewControllerC()
vcC.delegate = vcA // Connect delegate

调用以下代码后，ViewControllerC中的委托方法将起作用：

delegate?.userDidEnterInformation(textString)

---

在这里，通知中心可以代替代表成为一个很好的方法。使Viewcontroller成为观察者以接收文本信息，如下所示

在viewDidLoad（）中编写此代码

并在类Viewcontroller A中的任意位置编写此代码

func userDidEnterInformation(notification: Notification) {

    if let textInfo = notification.userInfo?["textInfo"] {
        textField.text = textInfo
    }
}

在Viewcontroller C中，通过编写以下代码，使用textInfo发布通知

NotificationCenter.default.post(name: NSNotification.Name.init(rawValue: "UserDidEnterInformation"), object: nil, userInfo: ["textInfo": textField.text])

---

考虑以下示例：-

let  aVCobjA = UIViewController()
let  aVCobjB = UIViewController()
let  aVCobjC = UIViewController()

var aNavigation = UINavigationController()

func pushVC()  {
    aNavigation.pushViewController(aVCobjA, animated: true)
    aNavigation.pushViewController(aVCobjB, animated: true)
    aNavigation.pushViewController(aVCobjC, animated: true)

    //Here you will get array of ViewControllers in stack of Navigationcontroller

    print(aNavigation.viewControllers)

    //To pass data from Viewcontroller C to ViewController A

    self.passData()

}

   // To pass data access stack of Navigation Controller as navigation controller provides a property viewControllers which gives you access of all view controllers that are pushed.

func passData()  {
    let aVCObj3 = aNavigation.viewControllers.last

    let aVCObj1 = aNavigation.viewControllers[0]

    //Now you have access to both view controller pass whatever data you want to pass
}

---

@amma teja希望使用委托模式传递数据根据我的要求，我编写了如下代码func userDidEnterInformation（notification:notification）{if let textInfo=notification.userInfo？[“textInfo”]{locationView.destination.text=textInfo}我在locationView.destination.text=textInfo中遇到错误，显示“无法将任何类型的值分配给类型字符串”@ammateja convert textInfo to string。文本信息作为？string此代码不起作用。如果我在ViewControllerC中写这个，它根本不属于ViewControllerC您是否正在使用视图控制器A和视图控制器C的导航控制器？@Leena am现在正在使用从viewController A到viewController B的navigationController和从viewController B到viewController C的navigationController，同时从viewController C到viewController A，我正在使用PoptorootViewController当您可以从navigationcontrolleri的堆栈访问视图控制器A时，我在viewcontrollerC中编写了此代码我需要如何调用viewcontrollerA？

NotificationCenter.default.post(name: NSNotification.Name.init(rawValue: "UserDidEnterInformation"), object: nil, userInfo: ["textInfo": textField.text])

let  aVCobjA = UIViewController()
let  aVCobjB = UIViewController()
let  aVCobjC = UIViewController()

var aNavigation = UINavigationController()

func pushVC()  {
    aNavigation.pushViewController(aVCobjA, animated: true)
    aNavigation.pushViewController(aVCobjB, animated: true)
    aNavigation.pushViewController(aVCobjC, animated: true)

    //Here you will get array of ViewControllers in stack of Navigationcontroller

    print(aNavigation.viewControllers)

    //To pass data from Viewcontroller C to ViewController A

    self.passData()

}

   // To pass data access stack of Navigation Controller as navigation controller provides a property viewControllers which gives you access of all view controllers that are pushed.

func passData()  {
    let aVCObj3 = aNavigation.viewControllers.last

    let aVCObj1 = aNavigation.viewControllers[0]

    //Now you have access to both view controller pass whatever data you want to pass
}