Swift学习笔记十六：协议

协议可以被类。枚举。结构体实现。满足协议要求的类，枚举，结构体被称为协议的遵循者。
遵循者须要提供协议指定的成员，如属性，方法，操作符，下标等。

一、协议的基本的语法

     咱们还是先上代码吧

protocol Human {
    var name:String{ get set }
    var isMan:Bool{set get}
    class var isUsable:Bool { set get }  //类成员。表示这个类是否可用
    func ageDescription(ages:Int...)     //函数參数能够是变长參数
}
class Student{
    var name = ""
}
class PrimaryStudent:Student,Human{
    class var isUsable:Bool{
        get{    return self.isUsable    }
        set{    self.isUsable = newValue    }
    }
    var isMan:Bool
    init(name:String,isMan:Bool){
        self.isMan = isMan
        super.init()
        self.name = name
    }
    func ageDescription(ages:Int...){
        var ageCount = 0
        for age in ages{
            ageCount += age;
        }
        println("this man age is \(ageCount)")
    }
}

protocol RandomNumberGenerator {
    func random() -> Double
}
class Dice {
    let sides: Int
    let generator: RandomNumberGenerator
    init(sides: Int, generator: RandomNumberGenerator) {
        self.sides = sides
        self.generator = generator
    }
    func roll() -> Int {
        return Int(generator.random() * Double(sides)) + 1
    }
}

class LinearCongruentialGenerator: RandomNumberGenerator {
    func random() -> Double {
        return random()%10.0
    }
}
var d6 = Dice(sides: 6,generator: LinearCongruentialGenerator())

protocol NameComplete {
    func nameSetCompleted(theName:String)
}
class Student{
    var delegate:NameComplete?
    var name:String{
    didSet{
        self.delegate?.nameSetCompleted(name)
    }
    }
    init(name:String,delegate:NameComplete){
        self.name = name
        self.delegate = delegate
    }
    
}
class DoSth:NameComplete{
    func nameSetCompleted(theName:String){
        println("name:\(theName) is set ")
    }
}
var a = DoSth()
var b = Student(name:"",delegate:a)
b.name = "小笨狼"  //输出：name:小笨狼 is set

@objc protocol Human{
    @optional var name:String{get set}
    @optional func descript()
}
class Student:Human{
    var name:String = "abc"
    func descript(){
    println("abc")
    }
}

protocol pName{
    var name:String{set get}
}
protocol dName:pName{
    func descript()
}
class Human:dName{
    var name = ""
    func descript(){
        println(name)
    }
}

protocol Named {
    var name: String { get }
}
protocol Aged {
    var age: Int { get }
}
struct Person: Named, Aged {
    var name: String
    var age: Int
}
func wishHappyBirthday(celebrator: protocol<Named, Aged>) {
    println("Happy birthday \(celebrator.name) - you're \(celebrator.age)!")
}
let birthdayPerson = Person(name: "Malcolm", age: 21)
wishHappyBirthday(birthdayPerson)   //输出Happy birthday Malcolm - you're 21!