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"
- }
- }
