初步swift语言学习笔记8(保留了很多ＯＣ实现)

笔者：fengsh998原文地址：http://blog.csdn.net/fengsh998/article/details/32715833转载请注明出处假设认为文章对你有所帮助，请通过留言或关注微信公众帐号fengsh998来支持我，谢谢！

虽然swift作为一门新语言，但还保留了很多ＯＣ的机制，使得swift和OC更好的融合在一起。假设没有ＯＣ基础的先ＧＯＯＧＬＥ一下。

如：ＫＶＯ。ＤＥＬＥＧＡＴＥ。ＮＯＴＩＦＩＣＡＴＩＯＮ。

详见ＤＥＭＯ。

import Foundation

@objc   // 须要打开objc标识，否则@optional编译出错

protocol kvoDemoDelegate {
func willDoSomething()
@optional  func didDoSomething()  //可选实现,
}

let ntfname = "test_notification"

class kvoDemo : NSObject //不写NSObject默认就是从NSObject来的
{
var delegate: kvoDemoDelegate!

var presult : Double = 0.0

var result : Double {
get{
return presult;
}

set{
self.presult = newValue
}
}

init()
{

}

func doSomething()
{
if let yet = self.delegate?
{
delegate!.willDoSomething()
}

for _ in 1..5
{
println("i'm doing now,don't touch me,please.")
}

if let yet = self.delegate?
{
delegate!.didDoSomething!()
}
}

func notificationPost()
{
let ntf = NSNotificationCenter.defaultCenter()
ntf.postNotificationName(ntfname, object :nil, userInfo:nil)
}

deinit
{

}
}

測试：

class ViewController: UIViewController,kvoDemoDelegate {

//KVO
override func observeValueForKeyPath(keyPath: String?, ofObject: AnyObject?, change: NSDictionary?, context: CMutableVoidPointer)
{
if keyPath == "result"
{
var newvalue : AnyObject?

= change?

.objectForKey("new");
println("the new value is \(newvalue)")
}
}

//delegate
func willDoSomething()
{
println("i will do it.")
}

func didDoSomething()
{
println("i had do it.")
}

//notification
func onRecviceNotification(notification:NSNotification)
{
println("Recevice notification \(notification)")
}

override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.

var kvo = kvoDemo()
kvo.addObserver(self, forKeyPath: "result", options: NSKeyValueObservingOptions.New | NSKeyValueObservingOptions.Old, context: nil)

kvo.result = 280.0

kvo.removeObserver(self,forKeyPath:"result",context: nil)

kvo.delegate = self
kvo.doSomething()

let ntf = NSNotificationCenter.defaultCenter()
ntf.addObserver(self, selector:"onRecviceNotification:", name :ntfname, object : nil)
kvo.notificationPost()
ntf.removeObserver(self)
}
}

结果：

the new value is 280
i will do it.
i'm doing now,don't touch me,please.
i'm doing now,don't touch me,please.
i'm doing now,don't touch me,please.
i'm doing now,don't touch me,please.
i had do it.
Recevice notification NSConcreteNotification 0x10be60930 {name = test_notification}