如何寻找到AVPlayer的最后一帧

import AVFoundation

// 创建AVPlayer对象
let url = URL(fileURLWithPath: "path/to/video.mp4")
let playerItem = AVPlayerItem(url: url)
let player = AVPlayer(playerItem: playerItem)

// 监听播放状态
playerItem.addObserver(self, forKeyPath: "status", options: .new, context: nil)
player.addObserver(self, forKeyPath: "rate", options: .new, context: nil)

// 播放视频
player.play()

// 监听播放状态的变化
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    if keyPath == "status" {
        if let playerItem = object as? AVPlayerItem {
            if playerItem.status == .readyToPlay {
                // 播放已经准备好
            }
        }
    } else if keyPath == "rate" {
        if let player = object as? AVPlayer {
            if player.rate == 0 && player.currentTime() == player.currentItem?.duration {
                // 播放结束，定位到最后一帧
                player.seek(to: CMTime(value: player.currentItem?.duration.value ?? 0, timescale: player.currentItem?.duration.timescale ?? 1))
            }
        }
    }
}