Xcode - 斯威夫特；为启动屏幕添加音效

Question

只是很快就想询问我在 swift 应用程序的启动屏幕中播放音效时遇到的一个小问题。对于我应该在哪里声明我的 AVAudio 播放器（在我的视图控制器或 Appdelegate 中），我更加困惑；但在这两种方法中都没有成功。这是我目前在我的 appDelegate 文件中得到的内容

import UIKit
import AVFoundation

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    var audioPlayer = AVAudioPlayer()

        func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
            // Override point for customization after application launch.

            self.window = UIWindow(frame: UIScreen.main.bounds)
            self.window!.backgroundColor = UIColor(red: 9/255, green: 4/255, blue: 68/255, alpha: 1)
            self.window!.makeKeyAndVisible()

            // rootViewController from StoryBoard
            let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
            let navigationController = mainStoryboard.instantiateViewController(withIdentifier: "navigationController")
            self.window!.rootViewController = navigationController

            // logo mask
            navigationController.view.layer.mask = CALayer()
            navigationController.view.layer.mask!.contents = UIImage(named: "logo.png")!.cgImage
            navigationController.view.layer.mask!.bounds = CGRect(x: 0, y: 0, width: 60, height: 60)
            navigationController.view.layer.mask!.anchorPoint = CGPoint(x: 0.5, y: 0.5)
            navigationController.view.layer.mask!.position = CGPoint(x: navigationController.view.frame.width / 2, y: navigationController.view.frame.height / 2)

            // logo mask background view
            let maskBgView = UIView(frame: navigationController.view.frame)
            maskBgView.backgroundColor = UIColor.white
            navigationController.view.addSubview(maskBgView)
            navigationController.view.bringSubview(toFront: maskBgView)

            // logo mask animation
            let transformAnimation = CAKeyframeAnimation(keyPath: "bounds")
            transformAnimation.delegate = self as? CAAnimationDelegate
            transformAnimation.duration = 1
            transformAnimation.beginTime = CACurrentMediaTime() + 1 //add delay of 1 second
            let initalBounds = NSValue(cgRect: (navigationController.view.layer.mask!.bounds))
            let secondBounds = NSValue(cgRect: CGRect(x: 0, y: 0, width: 50, height: 50))
            let finalBounds = NSValue(cgRect: CGRect(x: 0, y: 0, width: 2000, height: 2000))
            transformAnimation.values = [initalBounds, secondBounds, finalBounds]
            transformAnimation.keyTimes = [0, 0.5, 1]
            transformAnimation.timingFunctions = [CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut), CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)]
            transformAnimation.isRemovedOnCompletion = false
            transformAnimation.fillMode = kCAFillModeForwards
            navigationController.view.layer.mask!.add(transformAnimation, forKey: "maskAnimation")

            // logo mask background view animation
            UIView.animate(withDuration: 0.1,
                           delay: 1.35,
                           options: UIViewAnimationOptions.curveEaseIn,
                           animations: {
                            maskBgView.alpha = 0.0
            },
                           completion: { finished in
                            maskBgView.removeFromSuperview()
            })

            // root view animation
            UIView.animate(withDuration: 0.25,
                           delay: 1.3,
                           options: UIViewAnimationOptions(),
                           animations: {
                            self.window!.rootViewController!.view.transform = CGAffineTransform(scaleX: 1.05, y: 1.05)
            },
                           completion: { finished in
                            UIView.animate(withDuration: 0.3,
                                           delay: 0.0,
                                           options: UIViewAnimationOptions(),
                                           animations: {
                                            self.window!.rootViewController!.view.transform = CGAffineTransform.identity
                            },
                                           completion: nil
                            )

                            do {
                                self.audioPlayer = try AVAudioPlayer(contentsOf: URL.init(fileURLWithPath: Bundle.main.path(forResource: "startup", ofType: "wav")!))
                                self.audioPlayer.prepareToPlay()
                            }
                            catch {
                                print(error)
                            }
            })

            return true

    }



    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }


}

Answer 1

我更喜欢使用的方法是声明

var audioPlayer = AVAudioPlayer()

在 AppDelegate 中（就像您在代码中所做的那样）。

并且有一个播放音频的方法

func playSound(file:String, ext:String) -> Void {
    do {
        let url = URL.init(fileURLWithPath: Bundle.main.path(forResource: file, ofType: ext)!)
        audioPlayer = try AVAudioPlayer(contentsOf: url)
        audioPlayer.prepareToPlay()
        audioPlayer.play()
    } catch let error {
        NSLog(error.localizedDescription)
    }
}

这样就可以调用

playSound(file: "startup", ext: "wav")

在您的应用中随时随地播放此声音（以及其他声音），代码重复最少。

Answer 2

当我想在启动时进行握手时，我遇到了一些类似的问题。但根据 Apple UX，用户应该能够尽快着陆。

启动屏幕会在之前准备好您的视图和应用程序。我们无法控制它。 但是，如果我们不在着陆视图控制器中执行太多繁重的任务或在单独的线程中执行此操作，则可以减少启动屏幕时间。这样可以减少启动屏幕时间。

要实现这种音效，您可以创建一个初始 VC 并调用复制与启动屏幕相同的 UI，这样过渡就不会可见。在那里，您可以在viewDidLoad() 或viewDidAppear(animated:Bool) 中执行您的音频内容