Swift中KVC和KVO的使用

原创BLog，转载请注明出处

Swift中使用KVC和KVO的类都必须必须继承自NSObject

KVC

class TestForKVC:NSObject{
    var hwcCSDN = "hello world"
}
var instance = TestForKVC()
var value = instance.valueForKey("hwcCSDN") as String
instance.setValue("hello hwc",forKey:"hwcCSDN")

class ToObserver:NSObject{
    dynamic var hwcDate = NSDate()
    func updateDate(){
    hwcDate = NSDate()
    }
}

private var mycontext = 0

class TestForCSDN:UIViewController{
    var testVariable = ToObserver()
    override func viewDidLoad(){
	super.viewDidLoad()
	testVariable.addObserver(self,forKeyPath:"hwcDate",options:.New,context:&mycontext)
}
    deinit{
        testVariable.removeObserver(self,forKeyPath:"hwcDate")
    }
    overfide func observeValueForKeyPath(keyPath:String,ofObject:AnyObject,change:[NSObject:AnyObject],context:UnsafeMutablePointer<Void>){
        if(context == &mycontext){
             println("Changed to:\(change[NSKeyValueChangeNewKey]!)")
        }
    }
}

这样，就可以在函数observeValueForKeyPath检测到变化了

Swift中KVC和KVO的使用

原文：http://blog.csdn.net/hello_hwc/article/details/40590955