ios - 使用委托(delegate)/协议(protocol)将数据传递给第三方 View Controller

Question

我有 3 个 View Controller :http://i58.tinypic.com/2envu2x.png

View Controller 1 是第一个，它继续到 View Controller 2。 View Controller 3 是 View Controller 2 的 subview ，因为 View Controller 2 中有一个容器 View 。我需要将数据从 View Controller 1 传递到 View Controller 3。使用传统的委托(delegate)和协议(protocol)，我必须实际转至 View Controller 3 才能将数据传递给它。但是 segue 是从第一个 View Controller 到容器 View (第二个 View Controller )，而不是第三个。我如何修改委托(delegate)/协议(protocol)来实现这一点？

这是我的第一个 View Controller 的代码(它有一个表格 View ，所以我将协议(protocol)放在表格单元格中):

import UIKit

 protocol DataEnteredDelegate {
func userDidCHooseClass(classChose: String)
}

class FirstTableViewCell: UITableViewCell {

var delegate:DataEnteredDelegate?
@IBAction func buttonTapped(sender: AnyObject) {

    let string = "che107"
    self.delegate?.userDidCHooseClass(string)
}




override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

override func setSelected(selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
   }

}

这是 View Controller 3 的代码，我想接收字符串的 View Controller :

  import UIKit

class SecondTBC: UITableViewController, DataEnteredDelegate {

var stringThing = String()

override func viewDidLoad() {
    super.viewDidLoad()

    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()




}

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

// MARK: - Table view data source

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    // #warning Potentially incomplete method implementation.
    // Return the number of sections.
    return 0
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete method implementation.
    // Return the number of rows in the section.
    return 0
}


override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("cell1", forIndexPath: indexPath) as! firstCell



    return cell
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "segue1" {
        var otherController = FirstTableViewCell()
        otherController.delegate = self
    }
}


       func userDidCHooseClass(classChose: String) {
    stringThing = classChose
   }

Answer 1

要在两个未连接的 View Controller 之间传递数据，您需要使用:

presentingViewController!.dismissViewControllerAnimated(true, completion: nil)

并像这样通过 viewWillDisappear 传输您的数据:

override func viewWillDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    if self.isBeingDismissed() {
        self.delegate?.acceptData(textFieldOutlet.text)
    }
}

我已经发布了 a tutorial ，其中包括一个您可以下载和检查的工作项目文件。

---

这是上下文中的模式示例。

View Controller 2:

// place the protocol in the view controller that is being presented
protocol PresentedViewControllerDelegate {
    func acceptData(data: AnyObject!)
}

class PresentedViewController: UIViewController {
    // create a variable that will recieve / send messages
    // between the view controllers.
    var delegate : PresentedViewControllerDelegate?
    // another data outlet
    var data : AnyObject?


    @IBOutlet weak var textFieldOutlet: UITextField!
    @IBAction func doDismiss(sender: AnyObject) {
        if textFieldOutlet.text != "" {
            self.presentingViewController!.dismissViewControllerAnimated(true, completion: nil)
        }
    }


    override func viewDidLoad() {
        super.viewDidLoad()
        print("\(data!)")

        // Do any additional setup after loading the view.
    }

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


    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        if self.isBeingDismissed() {
            self.delegate?.acceptData(textFieldOutlet.text)
        }
    }

}

View Controller 1:

class ViewController: UIViewController, PresentedViewControllerDelegate {

    @IBOutlet weak var textOutlet: UILabel!
    @IBAction func doPresent(sender: AnyObject) {
        let pvc = storyboard?.instantiateViewControllerWithIdentifier("PresentedViewController") as! PresentedViewController

        pvc.data = "important data sent via delegate!"
        pvc.delegate = self
        self.presentViewController(pvc, animated: true, completion: nil)
    }

    override func viewDidLoad() {
        super.viewDidLoad()

    }

    func acceptData(data: AnyObject!) {     
        self.textOutlet.text = "\(data!)"

    }
}