我正在尝试在我用
Swift编写的iOS应用程序中采用ReactiveCocoa.不幸的是,看起来rac_valuesForKeyPath不能按预期工作.
这是一个例子：
这是一个例子：
class Source: NSObject {
var observable: String = "<Original>"
override init() {
super.init()
dispatch_after(dispatch_time(DISPATCH_TIME_NOW,Int64(1 * NSEC_PER_SEC)),dispatch_get_main_queue(),{ () -> Void in
self.observable = "<Updated>"
println("Updated value to \(self.observable)");
})
}
}
class Observer: NSObject {
init(source: Source) {
super.init()
source.rac_valuesForKeyPath("observable",observer: self).subscribeNext { (value: AnyObject!) -> Void in
println(">>> Observable value changed: \(value)")
}
}
}
>>> Observable value changed: <Original> Updated value to <Updated>
这意味着未调用subcribeNext块.
预期的输入是：
>>> Observable value changed: <Original> Updated value to <Updated> >>> Observable value changed: <Updated>
任何线索如何解决问题？
解决方法
可观察性需要是动态的
我让您的示例使用以下代码
class Source: NSObject {
dynamic var string:String = "Initial Value"
override init() {
super.init()
}
}
class Observer: NSObject {
init(source:Source) {
super.init()
source.rac_valuesForKeyPath("string",observer: self).subscribeNext { (newVal:AnyObject!) -> Void in
println(newVal)
}
}
}
class ViewController: UIViewController {
var source:Source!
var obs:Observer!
override func viewDidLoad() {
super.viewDidLoad()
source = Source()
obs = Observer(source: source)
source.string = "Another Value"
}
}
