簡(jiǎn)介

AirPlay是通過Wi-Fi連接支持AirPlay的設(shè)備，然后使用鏡像功能就能在其他設(shè)備顯示內(nèi)容，播放聲音。今天我要分享的是使用Airplay之后，我們要在電腦上顯示和iOS設(shè)備上顯示的內(nèi)容不一樣，簡(jiǎn)言之iOS設(shè)備類似于一個(gè)遙控器。
配合demo看感覺要好一些哇：https://github.com/Xcc1994/AirplayTestDemo

原理

獲取新的屏幕信息--->創(chuàng)建一個(gè)新的Window--->將新的Window對(duì)應(yīng)的Screen屏幕設(shè)置為新的屏幕--->設(shè)置新的屏幕的UI顯示

實(shí)現(xiàn)

 //連接Airplay Screen
    func connectScreen() {
        if UIScreen.screens.count > 1 {
            UIScreen.screens.forEach({[weak self] (screen:UIScreen) in
                if screen != UIScreen.main {
                    self?.didConnectScreen(screen: screen)
                }
            })
        }
    }
 //開始Airplay監(jiān)聽
    func beginReceivingScreenNotification() {
        //首先檢查是否已經(jīng)連接了
        connectScreen()
        //啟動(dòng)監(jiān)聽
        NotificationCenter.default.addObserver(self, selector: #selector(AirplayService.didReceiveConnectScreenNotification(noti:)), name: NSNotification.Name.UIScreenDidConnect, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(AirplayService.didReceiveDisConnectScreenNotification(noti:)), name: NSNotification.Name.UIScreenDidDisconnect, object: nil)
    }

每次我們創(chuàng)建一個(gè)工程都可以在AppDelegate文件中看見一個(gè)window，一般情況下我們可以不用理會(huì)它。screen我們拿來獲取一些屏幕信息之外也不會(huì)做其它處理。但是現(xiàn)在不一樣了，我們要實(shí)現(xiàn)多屏顯示，從需求也可以知道會(huì)多一個(gè)window。
我們啟動(dòng)程序的時(shí)候先去判斷現(xiàn)在screen的數(shù)量，未連接AirPlay進(jìn)行投屏的時(shí)候，我們的screen只有一個(gè)main screen。一旦連接AirPlay進(jìn)行投屏?xí)r遍歷現(xiàn)在的screen，除去main screen之外，我們還可以獲取在電腦上顯示的screen。
(啟動(dòng)監(jiān)聽的兩個(gè)通知后面再介紹……)

extension AirplayService:AirplayScreenDelegate {
    //已經(jīng)連接
    @objc func didConnectScreen(screen: UIScreen) {
        if currentViewController == nil {
            let defalutScreen =  DefalutViewController()
            currentViewController = defalutScreen
        }
        if screenWindow == nil {
            let window = UIWindow(frame: screen.bounds)
            screenWindow = window
            screenWindow?.rootViewController = currentViewController
            screenWindow?.isHidden = false
        }
        screenStatus = .Connected
        screenWindow?.screen = screen
        
        NotificationCenter.default.post(name: NSNotification.Name(rawValue: AirplayConstants.Notifications.ScreenDidConnected), object: nil)


    }
    //斷開連接
    @objc func didDisconnectScrren(screen: UIScreen) {
        screenStatus = .Disconnected
        NotificationCenter.default.post(name: NSNotification.Name(rawValue: AirplayConstants.Notifications.ScreenDidDisconnected), object: nil)
    }
}

一旦我們獲取到screen之后，我們就可以將新的Window對(duì)應(yīng)的Screen屏幕設(shè)置為新的屏幕。如果投屏的window當(dāng)前的currentViewController為nil ，我進(jìn)行了一個(gè)小處理寫了一個(gè)類似于屏保的默認(rèn)DefalutViewController。
現(xiàn)在我們來說說之前啟動(dòng)監(jiān)聽時(shí)發(fā)送的通知：

 //啟動(dòng)監(jiān)聽
 NotificationCenter.default.addObserver(self, selector: #selector(AirplayService.didReceiveConnectScreenNotification(noti:)), name: NSNotification.Name.UIScreenDidConnect, object: nil)
 NotificationCenter.default.addObserver(self, selector: #selector(AirplayService.didReceiveDisConnectScreenNotification(noti:)), name: NSNotification.Name.UIScreenDidDisconnect, object: nil)

    @objc func didReceiveConnectScreenNotification(noti:NSNotification) {
        let screen:UIScreen = noti.object as! UIScreen
        self.didConnectScreen(screen: screen)
    }
    
    @objc func didReceiveDisConnectScreenNotification(noti:NSNotification) {
        let screen:UIScreen = noti.object as! UIScreen
        self.didDisconnectScrren(screen: screen)
    }
    

我們連接AirPlay進(jìn)行投屏，可以有2種手順：
1、先連接AirPlay進(jìn)行投屏，再啟動(dòng)App君，這樣的話，我們啟動(dòng)App君的時(shí)候獲取screen的時(shí)候就可以獲取到多個(gè)screen，排除開main screen之外就可以進(jìn)行連接。
2、先啟動(dòng)App君，再連接AirPlay進(jìn)行投屏?；蛘呤沁\(yùn)行App君的過程中遇到奧特曼打小怪獸斷開了連接之后，世界和平之后又連接上的情況，我們就需要通過系統(tǒng)的兩個(gè)通知來解決問題了。

   @discardableResult func updateViewController(viewController:AirplayViewController,animation:Bool) -> Bool{
        guard screenWindow != nil else {
            return false
        }
        currentViewController?.airplayViewWillClose()
        currentViewController = viewController
        screenWindow?.rootViewController?.removeFromParentViewController()
        screenWindow?.rootViewController?.navigationController?.removeFromParentViewController()
        screenWindow?.rootViewController = nil
        screenWindow?.rootViewController = currentViewController
        currentViewController?.view.frame = (screenWindow?.bounds)!
        currentViewController?.view.layoutIfNeeded()
        currentViewController?.airplayViewWillShow()
        if animation {
            let maskView:UIView = UIView(frame: (currentViewController?.view.frame)!)
            maskView.backgroundColor = UIColor.black
            self.currentViewController?.view.addSubview(maskView)
            UIView.animate(withDuration: 0.5, animations: { 
                maskView.alpha = 0
            }, completion: { (finish:Bool) in
                maskView.removeFromSuperview()
                
            })
        }
        NotificationCenter.default.post(name: NSNotification.Name(rawValue: AirplayConstants.Notifications.ViewControllerDidUpdate), object: nil)
        return true
    }

這個(gè)是自己寫的一個(gè)更新電腦端Window的ViewController的一個(gè)動(dòng)畫。很簡(jiǎn)單就不說了。我是用Xcode8.1建的項(xiàng)目，用swift3.0的語法寫的，@discardableResult聲明是告訴編譯器此方法可以不用接收返回值。

測(cè)試

1、(真機(jī))使用AirServer軟件實(shí)現(xiàn)AirPlay，一定要打開鏡像

FullSizeRender.jpg

2、(模擬器)

屏幕快照 2017-01-13 12.56.17.png