zoukankan      html  css  js  c++  java
  • Swift 使用代理和闭包(closure)反向传值

    FirstViewController的代码


    import UIKit
    class FirstViewController: UIViewController, SecondViewControllerDelegate { @IBOutlet weak var showTextLabel: UILabel! @IBOutlet weak var showDelegateTextLabel: UILabel! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. } //点击按钮跳转到SecondViewController @IBAction func tapGoSecondViewController(sender: UIButton) { //从storyboard上加载SecondViewController let secondVC = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateViewControllerWithIdentifier("secondViewController") as! SecondViewController //实现回调,获取回调回来的值 (闭包) secondVC.backClosure = { (backStr: String) -> Void in self.showTextLabel.text = backStr } secondVC.delegate = self //跳转到SecondViewController self.navigationController?.pushViewController(secondVC, animated: true) } //MARK: - SecondViewControllerDelegate(代理) func fetchBackString(str: String) { self.showDelegateTextLabel.text = str } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } }

    SecondViewController的代码

    import UIKit
    
    //定义闭包类型(特定的函数类型函数类型)
    typealias InputClosureType = (String) -> Void
    
    protocol SecondViewControllerDelegate: NSObjectProtocol{
        func fetchBackString(str: String)
    }
    
    class SecondViewController: UIViewController {
        
        @IBOutlet weak var inputTextField: UITextField!
        //接收上个页面传过来的闭包块
        var backClosure: InputClosureType?
        weak var delegate: SecondViewControllerDelegate?
        
        override func viewDidLoad() {
            super.viewDidLoad()
    
            // Do any additional setup after loading the view.
        }
    
        @IBAction func tapBackButton(sender: UIButton) {
            if self.backClosure != nil {
                if let tempString = self.inputTextField.text {
                    self.backClosure!(tempString)
                }
            }
            self.navigationController?.popViewControllerAnimated(true)
        }
        
        @IBAction func delegateBackMethod(sender: UIButton) {
            if self.delegate != nil {
                if let tempString = self.inputTextField.text {
                    delegate!.fetchBackString("代理返回数据:(tempString)")
                }
            }
            self.navigationController?.popViewControllerAnimated(true)
        }
        
        override func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
            // Dispose of any resources that can be recreated.
        }
    }

    效果视图:

     

  • 相关阅读:
    今天把Oxite给部署起来了!
    PC游戏领域十年间十大败笔
    每天的流水账(2009916)
    小黑颠覆之作 ThinkPad Edge 13真机试用
    向大师们学习Javascript(视频、PPT)
    Google手机Nexus One单挑iPhone、HTC Hero 多图
    福布斯评下一个比尔·盖茨:一半来自中国
    每天的流水账(2009915)
    场地简介
    腾讯品牌形象店即将完工 设计曝光
  • 原文地址:https://www.cnblogs.com/xilanglang/p/5149840.html
Copyright © 2011-2022 走看看