解决方法
我的建议是使用KVC.也许不是最优雅的解决方案,但在概念上是KVC的逻辑应用.
观察属性的更改.注册init中的更改(entity：insertIntoManagedObjectContext :)或者在awakeFromFetch和awakeFromInsert中更好,并删除willTurnIntoFault中的观察者.
init(entity: NSEntityDescription!,insertIntoManagedObjectContext context: NSManagedObjectContext!) {
super.init(entity: entity,insertIntoManagedObjectContext: context)
addObserver(self,forKeyPath: "attribute",options: NSKeyValueObservingOptions.New | NSKeyValueObservingOptions.Old,context: nil)
}
override func observeValueForKeyPath(keyPath: String!,ofObject object: AnyObject!,change: NSDictionary!,context: CMutableVoidPointer) {
if (keyPath == "attribute") {
// do what you need to do
}
}
针对Swift 3进行了更新：
init(entity: NSEntityDescription!,options: [.old,.new],context: nil)
}
override func observeValue(forKeyPath keyPath: String?,of object: Any?,change: [NSKeyValueChangeKey : Any]?,context: UnsafeMutableRawPointer?) {
if keyPath == "attribute" {
// do what you need to do
}
}
