【发布时间】：2020-10-10 11:28:55
【问题描述】：
只是想弄清楚如何在 SwiftUI 中知道用户是否点击了播放/暂停按钮？
如果用户点击暂停/播放按钮，我需要我的媒体播放器暂停或播放。
我见过这样的例子
override func pressesBegan(presses: Set<UIPress>, withEvent event: UIPressesEvent?) {
if(presses.first?.type == UIPressType.PlayPause) {
pushedPlay()
// don't call to super class
}
}
但这不起作用 - 实际上应用程序不会运行。
也看到了这个例子
override func pressesEnded(_ presses: Set<UIPress>, with event: UIPressesEvent?)
{
for press in presses
{
if press.type == UIPress.PressType.playPause
{
// handle play pause action
break
}
else
{
super.pressesEnded(presses, with: event)
}
}
}
但是我不能把它放在我的 MusicPlayer.swift 文件中，因为它不会覆盖任何东西。
我也不能放进去
//
// ContentView.swift
// DRN1
//
// Created by Russell Harrower on 10/10/20.
//
import SwiftUI
import AVKit
struct ContentView: View {
var body: some View {
VStack{
Text("Testing Music Player").font(.headline).bold().multilineTextAlignment(.leading)
Spacer()
}
.onAppear {
// self.navigationViewStyle(StackNavigationViewStyle())
MusicPlayer.shared.startBackgroundMusic(url: "http://stream.radiomedia.com.au:8006/stream", type: "radio")
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
MusicPlayer.swift
import SwiftUI
//import Foundation
import AVFoundation
import MediaPlayer
import AVKit
struct NowPlayingData: Codable, Identifiable {
var id = UUID()
var artist : String
var song : String
var cover : String
}
class MusicPlayer{
static let shared = MusicPlayer()
static var mediatype = ""
static var artist = ""
static var song = ""
static var cover = ""
static var uuid = UIDevice.current.identifierForVendor?.uuidString
var player: AVPlayer?
let playerViewController = AVPlayerViewController()
func gettype(completion: @escaping (String) -> Void){
completion(MusicPlayer.mediatype)
}
func getPodCastPlayerNP(completion: @escaping (NowPlayingData) -> ()) {
// Timer.scheduledTimer(withTimeInterval: 15, repeats: true) { (timer) in
let songdata = "{\"id\": \"1\",\"song\": \"\(MusicPlayer.song)\",\"artist\": \"\(MusicPlayer.artist)\", \"cover\": \"\(MusicPlayer.cover)\"}"
let data: Foundation.Data = songdata.data(using: .utf8)!
let podcast = try! JSONDecoder().decode(NowPlayingData.self, from: data)
//print(data!)
// let episode = podcast.programs
DispatchQueue.main.async{
// The array is stored under programs now
//print(podcast)
completion(podcast)
}
// }
}
func startBackgroundMusic(url: String, type:String) {
MusicPlayer.mediatype = String(type)
//let urlString = "http://stream.radiomedia.com.au:8003/stream"
let urlString = url+"?uuid="+MusicPlayer.uuid!
print(urlString)
guard let url = URL.init(string: urlString) else { return }
let playerItem = AVPlayerItem.init(url: url)
player = AVPlayer.init(playerItem: playerItem)
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default, options: [.duckOthers, .mixWithOthers, .allowAirPlay])
print("Playback OK")
// let defaults = UserDefaults.standard
// defaults.set("1", forKey: defaultsKeys.musicplayer_connected)
try AVAudioSession.sharedInstance().setActive(true)
print("Session is Active")
} catch {
// let defaults = UserDefaults.standard
// defaults.set("0", forKey: defaultsKeys.musicplayer_connected)
print(error)
}
#if targetEnvironment(simulator)
self.playerViewController.player = player
self.playerViewController.player?.play()
print("SIMULATOR")
#else
self.setupRemoteTransportControls()
player?.play()
#endif
}
func startBackgroundMusicTwo() {
let urlString = "http://stream.radiomedia.com.au:8003/stream"
//let urlString = url
guard let url = URL.init(string: urlString) else { return }
let playerItem = AVPlayerItem.init(url: url)
player = AVPlayer.init(playerItem: playerItem)
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default, options: [.duckOthers, .mixWithOthers, .allowAirPlay])
print("Playback OK")
// let defaults = UserDefaults.standard
// defaults.set("1", forKey: defaultsKeys.musicplayer_connected)
try AVAudioSession.sharedInstance().setActive(true)
print("Session is Active")
} catch {
// let defaults = UserDefaults.standard
// defaults.set("0", forKey: defaultsKeys.musicplayer_connected)
print(error)
}
#if targetEnvironment(simulator)
self.playerViewController.player = player
self.playerViewController.player?.play()
print("SIMULATOR")
#else
self.setupRemoteTransportControls()
player?.play()
#endif
}
func setupRemoteTransportControls() {
// Get the shared MPRemoteCommandCenter
let commandCenter = MPRemoteCommandCenter.shared()
// Add handler for Play Command
commandCenter.playCommand.addTarget { [unowned self] event in
if self.player?.rate == 0.0 {
self.player?.play()
return .success
}
return .commandFailed
}
// Add handler for Pause Command
commandCenter.pauseCommand.addTarget { [unowned self] event in
if self.player?.rate == 1.0 {
self.player?.pause()
return .success
}
return .commandFailed
}
// self.nowplaying(artist: "Anna", song: "test")
}
func nowplaying(with artwork: MPMediaItemArtwork, artist: String, song: String){
MPNowPlayingInfoCenter.default().nowPlayingInfo = [
MPMediaItemPropertyTitle:song,
MPMediaItemPropertyArtist:artist,
MPMediaItemPropertyArtwork: artwork,
MPNowPlayingInfoPropertyIsLiveStream: true
]
// self.getArtBoard();
}
func setupNowPlayingInfo(with artwork: MPMediaItemArtwork) {
MPNowPlayingInfoCenter.default().nowPlayingInfo = [
// MPMediaItemPropertyTitle: "Some name",
// MPMediaItemPropertyArtist: "Some name",
MPMediaItemPropertyArtwork: artwork,
//MPMediaItemPropertyPlaybackDuration: CMTimeGetSeconds(currentItem.duration),
//MPNowPlayingInfoPropertyPlaybackRate: 1,
//MPNowPlayingInfoPropertyElapsedPlaybackTime: CMTimeGetSeconds(currentItem.currentTime())
]
}
func getData(from url: URL, completion: @escaping (UIImage?) -> Void) {
URLSession.shared.dataTask(with: url, completionHandler: {(data, response, error) in
if let data = data {
completion(UIImage(data:data))
}
})
.resume()
}
func getArtBoard(artist: String, song: String, cover: String) {
// MusicPlayer.JN = "[{'artist': \(artist), 'song':\(song), 'cover': \(cover)}]"
MusicPlayer.artist = artist
MusicPlayer.song = song
MusicPlayer.cover = cover
guard let url = URL(string: cover) else { return }
getData(from: url) { [weak self] image in
guard let self = self,
let downloadedImage = image else {
return
}
let artwork = MPMediaItemArtwork.init(boundsSize: downloadedImage.size, requestHandler: { _ -> UIImage in
return downloadedImage
})
self.nowplaying(with: artwork, artist: artist, song: song)
}
}
func stopBackgroundMusic() {
guard let player = player else { return }
player.pause()
}
}
还尝试添加：
func onPlayPauseCommand(perform action: (() -> Void)?) -> ContentView{
MusicPlayer.shared.player?.pause()
}
到我的内容视图，但它有一个错误
Cannot convert return expression of type 'Void?' to return type 'ContentView'
** 更新 **
所以我尝试使用以下内容：
struct ContentView: View {
@State var showingDetail = false
@State var showDetail = String(false)
var body: some View {
VStack{
Text("Interactive Radio").font(.headline).bold().multilineTextAlignment(.leading)
Text(showDetail)
Spacer()
}
.onAppear {
// self.navigationViewStyle(StackNavigationViewStyle())
MusicPlayer.shared.startBackgroundMusic(url: "http://url.com/stream", type: "radio")
print(self.showingDetail)
}
.onPlayPauseCommand(perform: {
MusicPlayer.shared.player?.pause()
})
}
}
但没有成功。我也试过长按也没有触发
.onLongPressGesture(minimumDuration: 0.5, perform: {
print("hello")
})
** 已解决 **
请注意为什么以下内容可以正常工作
//
// ContentView.swift
// DRN1
//
// Created by Russell Harrower on 10/10/20.
//
import SwiftUI
import AVKit
struct ContentView: View {
@State var showingDetail = false
@State var showDetail = String(false)
var body: some View {
Button(action: {
print("hello")
}, label: {
Text("Button")
})
.onAppear {
// self.navigationViewStyle(StackNavigationViewStyle())
MusicPlayer.shared.startBackgroundMusic(url: "http://URL:8006/stream", type: "radio")
print(self.showingDetail)
}
.onPlayPauseCommand(perform: {
if(MusicPlayer.shared.player?.rate != 0)
{
MusicPlayer.shared.player?.pause()
}
else{
MusicPlayer.shared.player?.play()
}
})
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
【问题讨论】：
-
它是通过什么方式崩溃的，Xcode中出现了哪些错误信息？
-
它只是带了一个红色的 X 并且不会运行脚本
-
"red X"，这是一个错误，不是崩溃，通过点击"red X" Xcode 会尝试解释问题。