Music App

這份作業花了很多心力，從選擇音樂、畫面呈現的色調到UI安排最後是程式碼的編寫，隨著功能越來越完善就像看著自己的孩子長大一樣，我也越發有成就感，不過目前尚有我覺得不足的地方，未來打算慢慢將其補齊。

利用AVPlayer播放音樂：

func playSong() {
        let playerItem = AVPlayerItem(url: songs[currentSongIndex].songUrl)
        player.replaceCurrentItem(with: playerItem)
        timePass = AVPlayerItem(url: songs[currentSongIndex].songUrl).asset.duration.seconds
        albumCoverImageView.image = songs[currentSongIndex].albumCover
        songOfTitleLabel.text = songs[currentSongIndex].songOfTitle
        singerLabel.text = songs[currentSongIndex].singer
        player.play()
        playpauseButton.setImage(UIImage(systemName: "pause.fill"), for: .normal)
        
        let duration = CMTimeGetSeconds(playerItem.asset.duration)
        songOfTimeLabel.text = timeFormatChange(time: duration)
        
        progressBarSlider.setValue(Float(0), animated: true)
        let targetTime: CMTime = CMTimeMake(value: Int64(0), timescale: 1)
        player.seek(to: targetTime)
        
        progressBarSlider.minimumValue = 0
        progressBarSlider.maximumValue = Float(duration)
        
        addProgressObserver(playerItem: playerItem)
    }

上下一首的功能：

@IBAction func nextSong() {
        switch playType {
        case .typeDefault:
            if currentSongIndex == 6 {
                currentSongIndex = 0
            }
            else {
                currentSongIndex += 1
            }
            playSong()
        case .typeLoopOne:
            if currentSongIndex == 6 {
                currentSongIndex = 0
            }
            else {
                currentSongIndex += 1
            }
            playSong()
        case .typeRandom:
            currentSongIndex = Int.random(in:0...6)
            playSong()
        }
    }
    
    @IBAction func previousSong() {
        switch playType {
        case .typeDefault:
            if currentSongIndex == 0 {
                currentSongIndex = 6
            }
            else {
                currentSongIndex -= 1
            }
            playSong()
        case .typeLoopOne:
            if currentSongIndex == 0 {
                currentSongIndex = 6
            }
            else {
                currentSongIndex -= 1
            }
            playSong()
        case .typeRandom:
            currentSongIndex = Int.random(in:0...6)
            playSong()
        }
    }

調整音量：

@IBAction func volumeChange(_ sender: UISlider) {
        player.volume = sender.value
    }

還有一些進階的功能就不一一細說，舉凡隨機播放開關、循環方式切換、還有播放時長等等都可以上我的github看看喔，也歡迎多給我一些指點，非常感謝。

操作影片：

HW7-2.mp4

程式碼：

GitHub - RubioLin/playerdemo

參考網站：

#94 模仿 iOS 的 Music App 製作情歌點唱機

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