#avaudioplayer

The AVAudioPlayer class can be used to Fade in and Out Music. In this tutorial a music track will be played, and the user can fade the music in or out using a switch, This tutorial is made with Xcode 10 and built for iOS 12.

Open Xcode and create a new Single View App.

For product name, use IOSFadeMusicTutorial and then fill out the Organization Name and Organization Identifier with your customary values. Enter Swift as Language and choose Next.

For this project we need a music to play. Download the music file. Open the Assets Catalog and drag the file inside te catalog.

Go to the Storyboard and drag  a Label, a Switch and another Label to the top of the main View, positioning them next to each other. Select the left Label and give it a title of "Fade out". Select the right Label and give it a title of "Fade in". Hold the Ctrl key and select all three items. Go to the bottom-right of the Storyboard, click the "Embed in " button and select Stack View.

Select the Stack View and go to the Attributes inspector. In the Stack View section change the Distribution field to "Equal Spacing".

go to the bottom-right of the Storyboard and select the Resolve Auto-Layout button and select Reset to suggested Constraints.

The Storyboard will look like this.

Select the Assistant Editor and make sure the ViewController.swift is visible next to the Storyboard. Ctrl-drag or right-click-drag from the Button to the class and create the following Action.

Go to the ViewController.swift file and import the AVFoundation framework.

import AVFoundation

Add the following property

var player: AVAudioPlayer!

Change the viewDidLoad method to 

override func viewDidLoad() { super.viewDidLoad() guard let asset = NSDataAsset(name: "com-truise-cyanide-sisters") else { print("Error Loading Audio."); return } do { player = try AVAudioPlayer(data: asset.data) } catch { print("Error Playing Audio."); return } player.volume = 0 player.numberOfLoops = -1 player.play() }

The music track will be played continuously by giving a value of -1  of the numberOfLoops property. The volume of the music track wil be silent at start.

Next, implement the fadeSwitchChanged(_:) action method

@IBAction func fadeSwitchChanged(_ sender: UISwitch) { if sender.isOn { // Fading in player.setVolume(1, fadeDuration: 2) } else { // Fading out player.setVolume(0, fadeDuration: 2) } }

The start value of the switch will be On by default. In this case it is better to change the start value to Off, because the first switch change will be a fade in action. Go to the Storyboard, select the Switch and go to the Property inspector. Go to the Switch section and change the value to Off.

Build and Run the project, and change the switch to fade in or fade out the music

The AVAudioPlayer class provides playback of audio data. In this tuturial a music file will be played, paused and stopped. Furthermore, the track title and playing time will be displayed. This tutorial is made with Xcode 10 and built for iOS 12.

Open Xcode and create a new Single View App.

For product name, use IOSPlayMusicAVAudioPlayerTutorial and then fill out the Organization Name and Organization Identifier with your customary values. Enter Swift as Language and choose Next.

For this project we need the images for the play/pause and stop buttons and also the mp3 file. You can download them here. Extract the files and drag them from the Finder window to the Project folder. Make sure you copy the items into the destination's folder.

Go to the Storyboard and drag two Labels and two Buttons to the main View. Select each object and fill in the following values in the Size Inspector.

Top Label -> X: 16, Y: 56, Width: 343, Height:17

Middle Label -> X: 137, Y: 119, Width: 101, Height: 36

Left Button -> X: 16, Y: 220, Width: 119, Height: 102

Right Button -> X:258, Y: 220, Width: 101, Height: 102

Again select each object and add the following values in the Attributes Inspector

top Label: Center Alignment, Font - System 14.0

center Label: Center Alignment. Font - System Bold 30.0

left Button: Type -Custom, Image - playpause.png

right Button: Type - Custom, Image - stop.png

Press the "Resolve Auto Layout" button from the bottom-right in the Storyboard and select "Reset to Suggested Constraints".

The Storyboard should look like this

Select the Assistant Editor and make sure the ViewController.swift is visible. Ctrl and drag from the top Label and create the following Outlet.

Ctrl and drag from the bottom Label and create the following Outlet.

Ctrl and drag from the play/pause Image and create the following Action.

Ctrl and drag from the stop Image and create the following Action.

Go to the ViewController.swift file and import the AVFoundation framework

import AVFoundation

Add the folowing properties in the ViewController class

var audioPlayer = AVAudioPlayer() var isPlaying = false var timer:Timer!

The AVAudioPlayer class lets you play sound in any audio format available in iOS. With the isPlaying Boolean we'll determine if the music is currently playing. The Timer property is needed for displaying the current time in the music track.

Change the viewDidLoad method in

override func viewDidLoad() { super.viewDidLoad() trackTitle.text = "Future Islands - Tin Man" let path = Bundle.main.path(forResource: "Future Islands - Tin Man", ofType: "mp3")! let url = URL(fileURLWithPath: path) do { audioPlayer = try AVAudioPlayer(contentsOf: url) } catch { // can't load file } }

The track title is assigned to the track label. Next, the AVAudioplayer is initialized with the music file.Next, implement the playOrPauseMusic method

@IBAction func playOrPauseMusic(_ sender: Any) { if isPlaying { audioPlayer.pause() isPlaying = false } else { audioPlayer.play() isPlaying = true timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(updateTime), userInfo: nil, repeats: true) } }

First we check if the track is currently playing. If it is, we pause the track and change the isPlaying property. If the track isn't playing, we play it and change the isPlaying property. Then we'll create a Timer object, which will call the updateTime method every second. Let's implement this method.

@objc func updateTime() { let currentTime = Int(audioPlayer.currentTime) let minutes = currentTime/60 let seconds = currentTime - minutes * 60 playedTime.text = String(format: "%02d:%02d", minutes,seconds) as String }

The currentTime property of audioPlayer will be split up in minutes and seconds, which will be displayed to our playedTime property. Finally implement the stopSound method.

@IBAction func stopMusic(sender: AnyObject) { audioPlayer.stop() audioPlayer.currentTime = 0 isPlaying = false }

The audioplayer calls the stop method and the currentTime is reset, so the next time when the play button is pressed, it will be played from the start. The isPlaying property is set to false. Build and Run the project on a real device, press the play/pause and stop button to control the music.

The AVAudioPlayer class can be used to Fade in and Out Music. In this tutorial a music track will be played, and the user can fade the music in or out using a switch, This tutorial is made with Xcode 8.2.1 and built for iOS 10.2.

Open Xcode and create a new Single View Application.

For product name, use IOS10FadeMusicTutorial and then fill out the Organization Name and Organization Identifier with your customary values. Enter Swift as Language and make sure only iPhone is selected in Devices.

For this project we need a music to play. Download the music file. Open the Assets Catalog and drag the file inside te catalog.

Go to the Storyboard and drag  a Label, a Switch and another Label to the top of the main View, positioning them next to each other. Select the left Label and give it a title of "Fade out". Select the right Label and give it a title of "Fade in". Hold the Ctrl key and select all three items. Go to the bottom-right of the Storyboard and select the "Embed in Stack" button.

Select the Stack View, go to the bottom-right of the Storyboard and select the Pin Auto-Layout button (fourth button from the left). Pin  the Stack View to the left, top and right edgesand select "Items of New Constraints" at the Update Frames section. Select "Add 1 Constraint".

Select the Stack View and go to the Attributes inspector. In the Stack View section change the Distribution field to "Equal Spacing".

The Storyboard will look like this.

Select the Assistant Editor and make sure the ViewController.swift is visible next to the Storyboard. Ctrl-drag or right-click-drag from the Button to the class and create the following Action.

Go to the ViewController.swift file and import the AVFoundation framework.

import AVFoundation

Add the following property

var player: AVAudioPlayer!

Change the viewDidLoad method to 

override func viewDidLoad() { super.viewDidLoad() guard let asset = NSDataAsset(name: "thestonefoxes-everybodyknows") else { print("Error Loading Audio."); return } do { player = try AVAudioPlayer(data: asset.data) } catch { print("Error Playing Audio."); return } player.volume = 0 player.numberOfLoops = -1 player.play() }

The music track will be played continuously by giving a value of -1  of the numberOfLoops property. The volume of the music track wil be silent at start.

Next, implement the fadeSwitch action

@IBAction func fadeSwitchChanged(_ sender: UISwitch) { if sender.isOn { // Fading in player.setVolume(1, fadeDuration: 2) } else { // Fading out player.setVolume(0, fadeDuration: 2) } }

The start value of the switch will be On by default. In this case it is better to change the start value to Off, because the first switch change will be a fade in action. Go to the Storyboard, select the Switch and go to the Property inspector. Go to the Switch section and change the value to Off.

Build and Run the project, and change the switch to fade in or fade out the music