我们如何将闭包传递给应用程序流中的任何ViewController? [英] How can we pass the closures to any ViewController in the app flow?

问题描述

在View Controller A中，

In View Controller A,

var completionBlock: (((String) -> ()))? = nil

&我将完成块称为(ViewController A):

& I am calling the completion block like(ViewController A):

if let block = completionBlock {
     block("block data to pass") 
}

我不想将完成数据传递给ViewController B，相反，我想传递给从ViewController B呈现的ViewController C.

I don't want to pass the completion data to ViewController B, instead i want to pass to ViewController C which is presenting from ViewController B.

简单地说，我想将闭包数据从ViewController A传递到ViewController C.我知道如何通过委托传递数据，只是对闭包感到好奇?

In simple words, i want to pass the closure data to from ViewController A to ViewController C.I know how to pass data with delegates, just curious with closures?

我们如何实现?

推荐答案

这只是我为您快速编写的示例代码，您可以根据需要修改对象.希望能解决您的问题.

This is just a sample code i quickly wrote for you, you can modify objects based on your need. Hopefully will address your problem.

import UIKit

class ViewControllerA: UIViewController {
    var block:(((String) -> ()))? = { input in
        print(input)
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = "A"
        let VCB = ViewControllerB()
        let VCC = ViewControllerC()
        VCC.block = block
        VCB.VCC = VCC
        self.navigationController?.pushViewController(VCB, animated: true)

    }


}

class ViewControllerB: UIViewController {
    var VCC:ViewControllerC?
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = .gray

    }
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        if let VCC = VCC {
            self.present(VCC, animated: true, completion: nil)
        }
    }


}

class ViewControllerC: UIViewController {
    var block:(((String) -> ()))? = nil

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = .yellow
        //Will run the block that has been passed
        block?("test")
    }


}

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