Swift3.0－反向传值

桃扇骨 2023-10-17 10:16 28阅读 0赞

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)
        }
    }