由于您没有权限查看它，因此无法打开iCloud视频文件。”

可以使用以下代码来在iOS应用程序中请求iCloud权限并访问视频文件：

import MobileCoreServices
import UIKit
import AVKit

class ViewController: UIViewController, UIDocumentPickerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        askForiCloudAccess()
    }

    func askForiCloudAccess() {
        let fileManager = FileManager.default
        let containerURL = fileManager.url(forUbiquityContainerIdentifier: nil)
        if containerURL != nil {
            print("iCloud is enabled")
            let fileURL = containerURL?.appendingPathComponent("Documents").appendingPathComponent("video.mp4")
            let documentPicker = UIDocumentPickerViewController(url: fileURL!, in: .import)
            documentPicker.delegate = self
            documentPicker.modalPresentationStyle = .formSheet
            present(documentPicker, animated: true, completion: nil)
        } else {
            print("iCloud is not enabled")
        }
    }

    func documentPicker(_ controller: UIDocumentPickerViewController,
                        didPickDocumentsAt urls: [URL]) {
        guard let myURL = urls.first else {
            return
        }
        print("import result : \(myURL)")
        let player = AVPlayer(url: myURL)
        let playerViewController = AVPlayerViewController()
        playerViewController.player = player
        present(playerViewController, animated: true) {
            playerViewController.player?.play()
        }
    }

}