如何在SwiftUI中控制AVPlayer? [英] How to control AVPlayer in SwiftUI?
本文介绍了如何在SwiftUI中控制AVPlayer?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
在我的新SwiftUI项目中,我有一个AVPlayer,用于从url流媒体音乐。现在我需要通过滑块控制当前播放曲目的时间和音量,设计部分如下:
现在我可以使用Userdata最终类及其@发布的变量来控制播放器,如isPlaying:
final class UserData: ObservableObject {
// ...
@Published var player: AVPlayer? = nil
@Published var isPlaying: Bool = false
//...
func playPausePlayer(withSong song: Song, forPlaylist playlist: [Song]?) {
//...
if isPlaying {
player?.pause()
} else {
player?.play()
}
isPlaying.toggle()
}
}
很高兴知道这一部分是否有更好的决定🧐
问题是属性CurrentTime、持续时间我只能从player
或player?.currentItem
获取,所以我不能制作这样的滑块:
@EnvironmentObject var userData: UserData
// ...
Slider(value: userData.player?.currentItem?.currentTime()!, in: 0...userData.player?.currentItem?.duration as! Double, step: 1)
我如何控制这些东西?
推荐答案
我没有找到任何解决方案,所以尝试自己解决。我学习了一点Combine
框架,继承了AVPlayer
类,并在ObservableObject
协议下对其进行了签名,并使用了KVO
。也许这不是最好的解决方案,但它是有效的,希望有人能给我一些建议,以便在未来改进代码。以下是一些代码片段:
import Foundation
import AVKit
import Combine
final class AudioPlayer: AVPlayer, ObservableObject {
@Published var currentTimeInSeconds: Double = 0.0
private var timeObserverToken: Any?
// ... some other staff
// MARK: Publishers
var currentTimeInSecondsPass: AnyPublisher<Double, Never> {
return $currentTimeInSeconds
.eraseToAnyPublisher()
}
// in init() method I add observer, which update time in seconds
override init() {
super.init()
registerObserves()
}
private func registerObserves() {
let interval = CMTime(seconds: 1, preferredTimescale: CMTimeScale(NSEC_PER_SEC))
timeObserverToken = self.addPeriodicTimeObserver(forInterval: interval, queue: .main) {
[weak self] _ in
self?.currentTimeInSeconds = self?.currentTime().seconds ?? 0.0
}
}
// func for rewind song time
func rewindTime(to seconds: Double) {
let timeCM = CMTime(seconds: seconds, preferredTimescale: CMTimeScale(NSEC_PER_SEC))
self.seek(to: timeCM)
}
// sure I need to remove observer:
deinit {
if let token = timeObserverToken {
self.removeTimeObserver(token)
timeObserverToken = nil
}
}
}
// simplified slider
import SwiftUI
struct PlayerSlider: View {
@EnvironmentObject var player: AudioPlayer
@State private var currentPlayerTime: Double = 0.0
var song: Song // struct which contains the song length as Int
var body: some View {
HStack {
GeometryReader { geometry in
Slider(value: self.$currentPlayerTime, in: 0.0...Double(self.song.songLength))
.onReceive(self.player.currentTimeInSecondsPass) { _ in
// here I changed the value every second
self.currentPlayerTime = self.player.currentTimeInSeconds
}
// controlling rewind
.gesture(DragGesture(minimumDistance: 0)
.onChanged({ value in
let coefficient = abs(Double(self.song.songLength) / Double(geometry.size.width))
self.player.rewindTime(to: Double(value.location.x) * coefficient)
}))
}
.frame(height: 30)
}
}
}
VolumeView更新
对于音量控制,我创建了新的UIViewRepresentable
结构:
import SwiftUI
import UIKit
import MediaPlayer
struct MPVolumeViewRepresenter: UIViewRepresentable {
func makeUIView(context: Context) -> MPVolumeView {
let volumeView = MPVolumeView()
volumeView.showsRouteButton = false // TODO: 'showsRouteButton' was deprecated in iOS 13.0: Use AVRoutePickerView instead.
if let sliderView = volumeView.subviews.first as? UISlider {
// custom design colors
sliderView.minimumTrackTintColor = UIColor(red: 0.805, green: 0.813, blue: 0.837, alpha: 1)
sliderView.thumbTintColor = UIColor(red: 0.805, green: 0.813, blue: 0.837, alpha: 1)
sliderView.maximumTrackTintColor = UIColor(red: 0.906, green: 0.91, blue: 0.929, alpha: 1)
}
return volumeView
}
func updateUIView(_ uiView: MPVolumeView, context: UIViewRepresentableContext<MPVolumeViewRepresenter>) {
// nothing here. really, nothing
}
}
// and you can use it like:
struct VolumeView: View {
var body: some View {
HStack(alignment: .center) {
Image("volumeDown")
.renderingMode(.original)
.resizable()
.frame(width: 24, height: 24)
MPVolumeViewRepresenter()
.frame(height: 24)
.offset(y: 2) // centering
Image("volumeUp")
.renderingMode(.original)
.resizable()
.frame(width: 24, height: 24)
}.padding(.horizontal)
}
}
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