最近刚开始学习用swift写一个小应用，由于应用需要区分锁屏和home键，上网查了许久，终于找到了方法。

我们需要在AppDelegate.swift中的func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool方法中添加一个监听CFNotificationCenterAddObserver（_center:CFNotificationCenter!,_observer:UnsafeRawPointer!,_callBack:CFNotificationCallback!,_name:CFString!,_object:UnsafeRawPointer!,_suspensionBehavior:CFNotificationSuspensionBehavior)：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

let observer = UnsafeRawPointer(Unmanaged.passUnretained(self).toOpaque())

 CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(),

observer,

{ (_, observer, _, _, _) -> () in

if let observer = observer {                                                                                                                                                                            let mySelf = Unmanaged.fromOpaque(observer).takeUnretainedValue()                                       mySelf.callback() } },

"com.apple.springboard.lockstate" as CFString,

nil,

CFNotificationSuspensionBehavior.deliverImmediately)

return true  }

我们这个监听是基于Darwin层的监听CFNotificationCenterGetDarwinNotifyCenter()，当我们锁屏和解锁的时候，通知中心会广播一个消息"com.apple.springboard.lockstate"，当我们监听到后，我们便会调用callBack方法，我尝试写过自定义的callBack方法，但是总有错误，于是尝试使用闭包，但由于闭包无法获取上下文，所以我通过callBack中的传参observer使用Unmanaged.fromOpaque(observer).takeUnretainedValue()获取self，至此便能调用AppDelegate中的方法

---

注意

由于ios11.0以后的版本监听锁屏键通知消息出现了修改，如下:

IOS11以前 锁屏时:hasBlankedScreen lockcomplete lockstate 开启屏幕未解锁:无通知消息 解锁时:hasBlankedScreen lockstate

IOS11以后 锁屏时:hasBlankedScreen 开启屏幕未解锁: lockcomplete (只执行一次） lockstate(只执行一次） hasBlankedScreen（每次开启屏幕都执行一次） 解锁时:lockstate

因此，由于iOS11以后的版本锁屏消息更改了所以要兼容ios11的锁屏键听则需要对当前ios版本进行判断，修改后的锁屏听的代码如下：

  if #available(iOS 11.0, *) {
            CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), observer,{ (_, observer, _, _, _) -> () in
                if let observer = observer {
                    let mySelf = Unmanaged<AppDelegate>.fromOpaque(observer).takeUnretainedValue()
                    mySelf.isSaveData = false
                    mySelf.callback()
                }
            }, "com.apple.springboard.lockstate" as CFString, nil, CFNotificationSuspensionBehavior.deliverImmediately)
            
            CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), observer,{ (_, observer, _, _, _) -> () in
                if let observer = observer {
                    let mySelf = Unmanaged<AppDelegate>.fromOpaque(observer).takeUnretainedValue()
                    mySelf.isSaveData = true
                    mySelf.callback()
                }
            }, "com.apple.springboard.hasBlankedScreen" as CFString, nil, CFNotificationSuspensionBehavior.deliverImmediately)
            
            
            
        } else {
            
            CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), observer,{ (_, observer, _, _, _) -> () in
                if let observer = observer {
                    let mySelf = Unmanaged<AppDelegate>.fromOpaque(observer).takeUnretainedValue()
                    mySelf.callback()
                }
            }, "com.apple.springboard.lockstate" as CFString, nil, CFNotificationSuspensionBehavior.deliverImmediately)
            
        }

总结

新手刚学，知识水平有限，如有错误之处，还望指出