我使用 SwiftUI 创建了一个视频播放器，它使用 imagePickerController 加载视频，然后假设从设备检索后播放视频。我发现检索视频后视频播放器不刷新。我不确定如何提供刷新它所需的适当的 @State|@Binding 。
我学习了如何使用可用的在线资源编写视频播放器代码。我找到了一种从我的设备加载视频并将其加载到我的视频播放器的方法。但是，当我按下播放按钮时，加载视频后，只播放声音。我尝试将视频播放器设置为 @State|@Binding 但找不到解决方案，因为它似乎不是直观地这样做的。
谁能建议如何使用 SwiftUI 更新视频播放器的代码？
P.S.1）您必须使用实际设备来加载视频； 2) 滑块尚未工作。接下来我会继续努力。
披露：
我从在线资源中改编了此代码。
这项工作大部分的原始源代码可以在以下链接找到：
如何在 SwiftUI 中打开 ImagePicker？ https://stackoverflow.com/questions/56515871/how-to-open-the-imagepicker-in-swiftui
https://www.raywenderlich.com/5135-how-to-play-record-and-merge-videos-in-ios-and-swift https://www.raywenderlich.com/5135-how-to-play-record-and-merge-videos-in-ios-and-swift
https://medium.com/@chris.mash/avplayer-swiftui-part-2-player-controls-c28b721e7e27 https://medium.com/@chris.mash/avplayer-swiftui-part-2-player-controls-c28b721e7e27
import SwiftUI
import AVKit
import PhotosUI
import MobileCoreServices
struct ContentView: View {
@State var showImagePicker: Bool = false
@State var url: URL?
var body: some View {
ZStack {
VStack {
Button(action: {
withAnimation {
self.showImagePicker.toggle()
}
}) {
Text("Show image picker")
}
// The video player will needs to be a @State??? as it is not updated with UIView changes but works when no view changes occur.
PlayerContainerView(player: AVPlayer(url: url ?? URL(string: "https://bitdash-a.akamaihd.net/content/sintel/hls/playlist.m3u8")!))
}
if (showImagePicker) {
ImagePicker(isShown: $showImagePicker, url: $url)
}
}
}
}
struct PlayerView: UIViewRepresentable {
let player: AVPlayer
func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<PlayerView>) {
}
func makeUIView(context: Context) -> UIView {
return PlayerUIView(player: player)
}
}
class PlayerUIView: UIView {
private let playerLayer = AVPlayerLayer()
init(player: AVPlayer) {
super.init(frame: .zero)
playerLayer.player = player
layer.addSublayer(playerLayer)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
playerLayer.frame = bounds
}
}
struct PlayerContainerView : View {
@State var seekPos = 0.0
private let player: AVPlayer
init(player: AVPlayer) {
self.player = player
}
var body: some View {
VStack {
PlayerView(player: player)
PlayerControlsView(player: player)
}
}
}
struct PlayerControlsView : View {
@State var playerPaused = true
@State var seekPos = 0.0
let player: AVPlayer
var body: some View {
HStack {
Button(action: {
self.playerPaused.toggle()
if self.playerPaused {
self.player.pause()
}
else {
self.player.play()
}
}) {
Image(systemName: playerPaused ? "play" : "pause")
.padding(.leading, 20)
.padding(.trailing, 20)
}
Slider(value: $seekPos, from: 0, through: 1, onEditingChanged: { _ in
guard let item = self.player.currentItem else {
return
}
let targetTime = self.seekPos * item.duration.seconds
self.player.seek(to: CMTime(seconds: targetTime, preferredTimescale: 600))
})
.padding(.trailing, 20)
}
}
}
struct ImagePicker: UIViewControllerRepresentable {
@Binding var isShown: Bool
@Binding var url: URL?
class Coordinator: NSObject, UINavigationControllerDelegate, UIImagePickerControllerDelegate {
@Binding var isShown: Bool
@Binding var url: URL?
init(isShown: Binding<Bool>, url: Binding<URL?>) {
$isShown = isShown
$url = url
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
let info = convertFromUIImagePickerControllerInfoKeyDictionary(info)
guard let mediaType = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.mediaType)] as? String,
mediaType == (kUTTypeMovie as String),
let uiURL = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.mediaURL)] as? URL
else { return }
url = uiURL
isShown = false
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
isShown = false
}
}
func makeCoordinator() -> Coordinator {
return Coordinator(isShown: $isShown, url: $url)
}
func makeUIViewController(context: UIViewControllerRepresentableContext<ImagePicker>) -> UIImagePickerController {
let picker = UIImagePickerController()
picker.mediaTypes = [kUTTypeMovie as String]
picker.delegate = context.coordinator
return picker
}
func updateUIViewController(_ uiViewController: UIImagePickerController,
context: UIViewControllerRepresentableContext<ImagePicker>) {
}
}
fileprivate func convertFromUIImagePickerControllerInfoKeyDictionary(_ input: [UIImagePickerController.InfoKey: Any]) -> [String: Any] {
return Dictionary(uniqueKeysWithValues: input.map {key, value in (key.rawValue, value)})
}
fileprivate func convertFromUIImagePickerControllerInfoKey(_ input: UIImagePickerController.InfoKey) -> String {
return input.rawValue
}
#if DEBUG
struct ContentView_Previews : PreviewProvider {
static var previews: some View {
ContentView(showImagePicker: true)
}
}
#endif
视频播放器没有按预期播放视频，它只播放声音，表明它正在播放视频；但是，我看不到它正在播放。它仍然是一个黑匣子。
UPDATE:以下是完全编辑的代码，可以按预期工作（滑块除外），在下面的评论中得到了回答：
import SwiftUI
import AVKit
import PhotosUI
import MobileCoreServices
struct ContentView: View {
@State var showImagePicker: Bool = false
@State var url: URL?
var body: some View {
ZStack {
VStack {
Button(action: {
withAnimation {
self.showImagePicker.toggle()
}
}) {
Text("Show image picker")
}
PlayerContainerView(player: AVPlayer(url: url ?? URL(string: "https://bitdash-a.akamaihd.net/content/sintel/hls/playlist.m3u8")!))
}
if (showImagePicker) {
ImagePicker(isShown: $showImagePicker, url: $url)
}
}
}
}
struct PlayerView: UIViewRepresentable {
let player: AVPlayer
func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<PlayerView>) {
(uiView as? PlayerUIView)?.updatePlayer(player: player)
}
func makeUIView(context: Context) -> UIView {
return PlayerUIView(player: player)
}
}
class PlayerUIView: UIView {
private let playerLayer = AVPlayerLayer()
init(player: AVPlayer) {
super.init(frame: .zero)
playerLayer.player = player
layer.addSublayer(playerLayer)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
playerLayer.frame = bounds
}
func updatePlayer(player: AVPlayer) {
self.playerLayer.player = player
}
}
struct PlayerContainerView : View {
@State var seekPos = 0.0
private let player: AVPlayer
init(player: AVPlayer) {
self.player = player
}
var body: some View {
VStack {
PlayerView(player: player)
PlayerControlsView(player: player)
}
}
}
struct PlayerControlsView : View {
@State var playerPaused = true
@State var seekPos = 0.0
let player: AVPlayer
var body: some View {
HStack {
Button(action: {
self.playerPaused.toggle()
if self.playerPaused {
self.player.pause()
}
else {
self.player.play()
}
}) {
Image(systemName: playerPaused ? "play" : "pause")
.padding(.leading, 20)
.padding(.trailing, 20)
}
Slider(value: $seekPos, from: 0, through: 1, onEditingChanged: { _ in
guard let item = self.player.currentItem else {
return
}
let targetTime = self.seekPos * item.duration.seconds
self.player.seek(to: CMTime(seconds: targetTime, preferredTimescale: 600))
})
.padding(.trailing, 20)
}
}
}
struct ImagePicker: UIViewControllerRepresentable {
@Binding var isShown: Bool
@Binding var url: URL?
class Coordinator: NSObject, UINavigationControllerDelegate, UIImagePickerControllerDelegate {
@Binding var isShown: Bool
@Binding var url: URL?
init(isShown: Binding<Bool>, url: Binding<URL?>) {
_isShown = isShown
_url = url
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
let info = convertFromUIImagePickerControllerInfoKeyDictionary(info)
guard let mediaType = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.mediaType)] as? String,
mediaType == (kUTTypeMovie as String),
let uiURL = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.mediaURL)] as? URL
else { return }
url = uiURL
isShown = false
}
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
isShown = false
}
}
func makeCoordinator() -> Coordinator {
return Coordinator(isShown: $isShown, url: $url)
}
func makeUIViewController(context: UIViewControllerRepresentableContext<ImagePicker>) -> UIImagePickerController {
let picker = UIImagePickerController()
picker.mediaTypes = [kUTTypeMovie as String]
picker.delegate = context.coordinator
return picker
}
func updateUIViewController(_ uiViewController: UIImagePickerController,
context: UIViewControllerRepresentableContext<ImagePicker>) {
}
}
fileprivate func convertFromUIImagePickerControllerInfoKeyDictionary(_ input: [UIImagePickerController.InfoKey: Any]) -> [String: Any] {
return Dictionary(uniqueKeysWithValues: input.map {key, value in (key.rawValue, value)})
}
fileprivate func convertFromUIImagePickerControllerInfoKey(_ input: UIImagePickerController.InfoKey) -> String {
return input.rawValue
}
#if DEBUG
struct ContentView_Previews : PreviewProvider {
static var previews: some View {
ContentView(showImagePicker: true)
}
}
#endif
