Swift入门教程17-协议(二)

标签：swift   协议   补充   

原创Blog，转载请注明出处

http://blog.csdn.net/hello_hwc

本文主要补充上一篇文章中未提及的协议的功能

一、扩展中的协议

protocol TextProtocol {
	func asString() -> String
}
class ID{
	var ID:Int	 = 0
}
extension ID:TextProtocol{
	func asString()->String{
		return String(ID)
	}
}

class ID{
	var ID:Int = 0
	func asString()->String{
		return String(ID)
	}	
}
extension ID:TextProtocol

protocol HwcProtocol{
	func logDescription()
}
class Obj1:HwcProtocol{
	func logDescription(){
		println("From obj1")
	}
}
class Obj2:HwcProtocol{
	func logDescription(){
		println("From obj2")
	}
}
class Obj3:HwcProtocol{
	func logDescription(){
		println("From obj3")
	}
}
var obj1 = Obj1()
var obj2 = Obj2()
var obj3 = Obj3()
let things: [HwcProtocol] = [obj1,obj2,obj3]
for thing in things {
	println(thing.logDescription())
}

protocol InheritingProtocol: SomeProtocol, AnotherProtocol {
// 协议定义
}

protocol SomeClassOnlyProtocol: class, SomeInheritedProtocol {
// class-only protocol definition goes here
}

protocol Named {
	var name: String { get }
}
protocol Aged {
	var age: Int { get }
}
struct Person: Named, Aged {
	var name: String
	var age: Int
}
//这里protocol<Named, Aged>表示同时遵循两个协议的类型
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

@objc protocol CounterDataSource {
	optional func incrementForCount(count: Int) -> Int
	optional var fixedIncrement: Int { get }
}
@objc class Counter {
	var count = 0
	var dataSource: CounterDataSource?
	func increment() {
		if let amount = dataSource?.incrementForCount?(count) {
			count += amount
	} else if let amount = dataSource?.fixedIncrement? {
			count += amount
	}
	init(count:Int){
		self.count = count
	}
	}
}

class HwcTest:CounterDataSource{
	var counter:Counter
	init(counter:Counter){
		self.counter = counter;
		self.counter.dataSource = self;
	}
	var fixedIncrement = 10
	func hwcPrint(){
		for i in 1...10{
			println(counter.count)
			counter.increment()
		}
	}
}

class HwcTest:CounterDataSource{
	var counter:Counter
	init(counter:Counter){
		self.counter = counter;
		self.counter.dataSource = self;
	}
	func incrementForCount(count: Int)->Int{
		return count+1
	}
	func hwcPrint(){
		for i in 1...10{
			println(counter.count)
			counter.increment()
		}
	}
}

Swift入门教程17-协议(二)

标签：swift   协议   补充   

原文地址：http://blog.csdn.net/hello_hwc/article/details/41948501