KVO三板斧

  person.addObserver(self, forKeyPath: "name", options: .new, context: nil)
  override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) { }
 deinit {person.removeObserver(self, forKeyPath: "name") }

RxSwift的KVO封裝

1.rx.observe:高效，它是一個(gè) KVO 機(jī)制的簡(jiǎn)單封裝。

self.person.rx.observe(String.self, "name").subscribe(onNext: { (change) in
                print("observe訂閱到了KVO:\(String(describing: change))")
            }).disposed(by: disposeBag)

2.rx.observeWeakly:執(zhí)行效率低一些，它處理weak修飾的對(duì)象。

self.person.rx.observeWeakly(String.self, "name")
            .subscribe(onNext: { (change) in
                print("observeWeakly訂閱到了KVO:\(String(describing: change))")
            })
            .disposed(by: disposeBag)

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