swift-单例、属性传值、代理、闭包、通知传值

swift 也有和OC 一样的穿值方式

1.单例模式总结

final class LTSingle: NSObject {

    static let sharedInstance = LTSingle()

    private override init() {}

}

2.属性传值

很简单

在下一个界面(ViewController2)中声明

var name : String?

前一个界面(ViewController)中传值

let vc = ViewController2()

vc.name = "测试传值"

self.navigationController?.pushViewController(vc, animated: true)

3.代理

1>在下一个界面(ViewController3)中声明协议

protocol LTDelegate: NSObjectProtocol {

    func postValueToUpPage(str: String)

}

2>在class属性(ViewController3)中声明属性

weak var delegate: LTDelegate?

3>ViewController3调用方法

delegate?.postValueToUpPage(str: "传值到上一页")

4>在ViewController2中

class ViewController2: BaseViewController,LTDelegate {

5>在ViewController2遵守协议

let vc = ViewController3()

vc.delegate = self

self.navigationController?.pushViewController(vc, animated: true)

6>在ViewController2实现方法

//实现代理方法

    func postValueToUpPage(str: String) {

        print(str)

    }

4.闭包

1>在下一个界面(ViewController4)中声明

//1.声明

typealias nameBlock = (String) -> Void

2>在class属性(ViewController4)中声明

//2.重定义

var postNameValue:nameBlock?

3>ViewController4调用方法

override func didClick2() {

        if postNameValue != nil {

            postNameValue!("呵呵")

        }

        back()

    }

4>在ViewController3中

let vc = ViewController4()

vc.postNameValue = { (str) in

    print(str)

}

self.navigationController?.pushViewController(vc, animated: true)

貌似闭包更简单一点啊，哈哈

5.通知

1>在ViewController5中按钮点击事件中发送通知

//let dict = ["action":"通知传值"]

//NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationTest"), object: self, userInfo: dict)

NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationTest"), object: "通知传值")

2>在需要接受的通知的方法中，接受通知

NotificationCenter.default.addObserver(self, selector: #selector(didClick3(notififaction:)), name: NSNotification.Name.init("notificationTest"), object: nil)

3>实现方法

@objc func didClick3(notififaction : NSNotification) {

        let name = notififaction.object

        print(name as Any)

        //print(notififaction.userInfo!["action"] as Any)

    }

4>class中移除通知

deinit {

        NotificationCenter.default.removeObserver(self)

    }

demo点击下载