Swift3.0－反向传值

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Swift3.0－反向传值

1、使用代理协议

在ViewController.swift中

class ViewController: UIViewController,SubDelegate {    override func viewDidLoad() {        super.viewDidLoad()//        setNavigation()        myButton()    }            func myButton() {        let btn = UIButton(type:UIButtonType.system) as UIButton        btn.frame = CGRect(x:60,y:100,width:100,height:30)        btn.backgroundColor = UIColor.lightGray        btn.setTitle("进入下一界面", for: UIControlState.normal)        self.view.addSubview(btn)                btn.addTarget(self, action: #selector(click), for: UIControlEvents.touchUpInside)    }    func click(){        let vc = SubViewController()        vc.delegate = self//        let vc = SubClosureViewController()//        vc.changeTitleAndClosure = {//            (title:String,color:UIColor) in//            self.title = title//            self.view.backgroundColor = color//        }        self.navigationController?.pushViewController(vc, animated: true)    }        func changeTitle(title: String) {        self.title = title    }        func changeColor(color: UIColor) {        self.view.backgroundColor = color    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }}

在SubViewController.swift中

//在委托中定义协议protocol SubDelegate:NSObjectProtocol {    //实现一些方法    func changeTitle(title:String)    func changeColor(color:UIColor)}class SubViewController: UIViewController {    //定义遵守协议    var delegate:SubDelegate?        override func viewDidLoad() {        super.viewDidLoad()        myView()    }    func myView() {        self.view.backgroundColor = UIColor.red                let tf = UITextField(frame:CGRect(x:60,y:180,width:100,height:30))        tf.borderStyle = UITextBorderStyle.roundedRect        tf.tag = 100        self.view.addSubview(tf)                let btn = UIButton(type:UIButtonType.system) as UIButton        btn.frame = CGRect(x:60,y:100,width:100,height:30)        btn.backgroundColor = UIColor.lightGray        btn.setTitle("返回上一界面", for: UIControlState.normal)        self.view.addSubview(btn)                btn.addTarget(self, action: #selector(click), for: UIControlEvents.touchUpInside)    }    func click(){        let tf = self.view.viewWithTag(100) as? UITextField        delegate?.changeTitle(title: tf!.text!)        delegate?.changeColor(color: UIColor.blue)        self.navigationController?.popViewController(animated: true)    }}

2、使用闭包

在ViewController.swift中

class ViewController: UIViewController,SubDelegate {    override func viewDidLoad() {        super.viewDidLoad()//        setNavigation()        myButton()    }            func myButton() {        let btn = UIButton(type:UIButtonType.system) as UIButton        btn.frame = CGRect(x:60,y:100,width:100,height:30)        btn.backgroundColor = UIColor.lightGray        btn.setTitle("进入下一界面", for: UIControlState.normal)        self.view.addSubview(btn)                btn.addTarget(self, action: #selector(click), for: UIControlEvents.touchUpInside)    }    func click(){//        let vc = SubViewController()//        vc.delegate = self        let vc = SubClosureViewController()        vc.changeTitleAndClosure = {            (title:String,color:UIColor) in            self.title = title            self.view.backgroundColor = color        }        self.navigationController?.pushViewController(vc, animated: true)    }}

在SubClosureViewController.swift中

class SubClosureViewController: UIViewController {    //定义一个闭包    var changeTitleAndClosure:((_ title:String,_ color:UIColor) -> Void)?        override func viewDidLoad() {        super.viewDidLoad()        myView()    }    func myView() {        self.view.backgroundColor = UIColor.red                let tf = UITextField(frame:CGRect(x:60,y:180,width:100,height:30))        tf.borderStyle = UITextBorderStyle.roundedRect        tf.tag = 100        self.view.addSubview(tf)                let btn = UIButton(type:UIButtonType.system) as UIButton        btn.frame = CGRect(x:60,y:100,width:100,height:30)        btn.backgroundColor = UIColor.lightGray        btn.setTitle("返回上一界面", for: UIControlState.normal)        self.view.addSubview(btn)                btn.addTarget(self, action: #selector(click), for: UIControlEvents.touchUpInside)    }    func click(){        let tf = self.view.viewWithTag(100) as? UITextField        changeTitleAndClosure?(tf!.text!,UIColor.green)        self.navigationController?.popViewController(animated: true)    }}

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