如何将数据从一个容器传递到另一个容器，两者都嵌入在 swift 中的同一个 uiviewcontroller 中? [英] how can I pass data from one container to another, both embedded in the same uiviewcontroller in swift?

问题描述

我有一个父 UIViewController，它有两个不同的视图容器——每个容器都嵌入了 UIViewController.它看起来像这样:

I have a parent UIViewController and it has two different view containers - each of them has embedded UIViewController inside. It looks somehow like this:

当用户按下存储在左侧容器的按钮时，我想更改右侧容器上的标签.

I want to change the label on the right container when user presses the button stored on the left one.

到目前为止，我能够在父视图控制器中放置一个按钮的情况下做到这一点，然后我只是使用了一个协议:

So far I was able to do it while having a button placed in a parent view controller, then I was just using a protocol:

• 在我的父组件中:

• in my parent component I had:

class ParentController: UIViewController {

    var delegateEmbedded:HandleEmbedded?

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if (segue.identifier == "segueToFirstEmbeddedController"){

        if let embeddedView = segue.destinationViewController as? EmbeddedContainer {

           self.delegateEmbedded = embeddedView
         } 


     }

在我的容器嵌入式 UIViewController 中:

in my container-embedded UIViewController I had:

protocol HandleEmbedded: class {
    func setName(label: String)
}

class EmbeddedContainer: UITableViewController, HandleYourChat{

    func setName(label: String){
        print("setting label to (label)")
    }
}

当我将按钮放置在父控制器中并想要更改容器内的标签时，上述情况有效.但是，当按钮也被嵌入但在与标签不同的容器中时，会发生什么，我应该如何传递数据?我是否必须通过父控制器传递数据?这样做的最佳方法是什么?

Situation above works when I have the button placed in a parent controller and want to change the label inside a container. But what happens and how should I pass the data when the button is also embedded, but in a different container than the label? Do I have to pass the data through the parent controller? What's the best way for doing so?

推荐答案

要将数据从一个嵌入式 ViewController 传递到另一个嵌入式 ViewController，请让父级处理传输.在这里，我提供了一个完整的示例，其中包含三个 ViewController 和一个 StringTaker 协议.主要的 ViewController 和 LabelViewController 都实现了这个协议.主要的 ViewController 从 ButtonViewController 获取一个字符串并将其传递给嵌入的 LabelViewController.

To pass data from one embedded ViewController to another embedded ViewController, have the parent handle the transfer. Here I have provided a complete example with three ViewControllers and a single StringTaker protocol. Both the main ViewController and the LabelViewController implement this protocol. The main ViewController takes a string from the ButtonViewController and passes it on to the embedded LabelViewController.

ViewController.swift

import UIKit

protocol StringTaker: class {
    func takeString(string: String)
}

class ViewController: UIViewController, StringTaker {

    weak var stringTaker: StringTaker?

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "EmbedButtonViewController" {
            let dvc = segue.destinationViewController as! ButtonViewController
            dvc.delegate = self
        } else if segue.identifier == "EmbedLabelViewController" {
            let dvc = segue.destinationViewController as! LabelViewController
            stringTaker = dvc
        }
    }

    // Receive the string from the ButtonViewController
    func takeString(string: String) {
        // Pass it to the LabelViewController
        stringTaker?.takeString(string)
    }
}

ButtonViewController.swift

import UIKit

class ButtonViewController: UIViewController {

    weak var delegate: StringTaker?

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func generateString(sender: UIButton) {
        let cities = ["Boston", "Paris", "Sydney", "Mumbai", "Lima"]

        // Pick a random city
        let city = cities[Int(arc4random_uniform(UInt32(cities.count)))]

        // Pass the string to the delegate
        delegate?.takeString(city)
    }
}

LabelViewController.swift

import UIKit

class LabelViewController: UIViewController, StringTaker {

    @IBOutlet weak var myLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    func takeString(string: String) {
        myLabel.text = string
    }
}

<小时>

注意事项:

---

Things to note:

1. LabelViewController 和 ButtonViewController 对使用它们的 ViewController 一无所知.这使得重用它们变得更加容易.您可以将它们嵌入到另一个 viewController 中，只要您正确实现了 StringTaker 协议并设置了 delegate，一切正常.
2. 在命名嵌入转场然后在 prepareForSegue 中正确设置代表时，将其连接起来的关键.将 Container 添加到 ViewController 后，可以在 Document Outline 视图中找到 segue.

1. The LabelViewController and the ButtonViewController know nothing about the ViewController that uses them. This makes it easier to reuse them. You could embed them in another viewController and as long as you properly implement the StringTaker protocol and set up the delegate, everything works.
2. The key to hooking this up in in naming the embed segues and then properly setting up the delegates in prepareForSegue. The segues can be found in the Document Outline view once the Container is added to the ViewController.

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