在应用程序被杀死后请求使用通过 UIImagePickerController 选取的视频文件的权限

Question

所以我目前正在使用 UIImagePickerController 从图库中挑选视频。我有这个代码：

 func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        if let videoURL = info[UIImagePickerController.InfoKey.mediaURL] as? URL {
            MediaManager.shared.sourceType = picker.sourceType
            self.metadata.videoURL = videoURL
            ...
        }
        else if let asset =  info[UIImagePickerController.InfoKey.phAsset] as? PHAsset {
            asset.getURL(completionHandler: { url in
                self.metadata.videoURL = url
               ...
            })
        }
        else if let ref =  info[UIImagePickerController.InfoKey.phAsset] as? URL {
            self.metadata.videoURL = ref
           ...
        }
        else {
           ...
        }


    }

因此，我保存了视频 url 并基于此 url 我能够获取视频数据等

问题是，下次我重新启动应用程序时，我希望能够在不使用选择器的情况下再次获取该视频。但似乎我没有权限。有什么方法可以向 iOS 请求许可，即使我关闭了应用程序（或者它崩溃了），我也可以通过它的 url 打开视频？

编辑：

例如，我得到这样的东西 url:

file:///private/var/mobile/Containers/Data/Application/AC5AD743-924F-430D-9C34-F3848E4CEE75/tmp/4CBAD829-8764-4234-BCCF-BFA571845D55.MOV

但是应用被kill后我真的不能用了。那么如何用picker挑选东西，以后再用呢

Answer 1

Apple documentation 说：

Important: Although they are safe to use while your app is running, file reference URLs are not safe to store and reuse between launches of your app because a file’s ID may change if the system is rebooted. If you want to store the location of a file persistently between launches of your app, create a bookmark as described in Locating Files Using Bookmarks.

所以我建议使用 bookmarkData(options:includingResourceValuesForKeys:relativeTo:) 方法为现有 URL 创建书签。

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
        guard let mediaType = info[.mediaType] as? String,
            mediaType == kUTTypeMovie as String,
            let url = info[.mediaURL] as? URL else {
            return
        }

        do {
            let bookmarkData = try url.bookmarkData()
            UserDefaults.standard.set(bookmarkData, forKey: "mediaURL")
        } catch {
            print("bookmarkData error: \(error)")
        }
    }

    func mediaURL() -> URL? {
        guard let urlData = UserDefaults.standard.data(forKey: "mediaURL") else {
            return nil
        }

        var staleData = false
        let mediaURL = try? URL(resolvingBookmarkData: urlData, options: .withoutUI, relativeTo: nil, bookmarkDataIsStale: &staleData)

        return staleData ? nil : mediaURL
    }

Answer 2

改编@Michcio 的回答，你可以这样做：

Select 视频事件：

public func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {

    let mediaType = info[UIImagePickerController.InfoKey.mediaType] as AnyObject
    if mediaType as! String == kUTTypeMovie as String {
        guard let videoURL = info[UIImagePickerController.InfoKey.mediaURL] as? URL else {
            return
        }
        let bookmarkData: Data

        do {
            try bookmarkData = videoURL.bookmarkData()
            let userDefaults = UserDefaults.standard
            userDefaults.set(bookmarkData, forKey: "video")
            userDefaults.synchronize()
        } catch {
            print(error)
        }

        self.pickerController.dismiss(animated: true, completion: nil)
    }

}

重启后恢复视频URL：

func getVideo() {

    let userDefaults = UserDefaults.standard
    guard let decoded  = userDefaults.data(forKey: "video") else {
        return
    }

    var videoURL: NSURL

    do {
        var isSSNField = ObjCBool(true)
        try videoURL = NSURL.init(resolvingBookmarkData: decoded, options: .withoutUI, relativeTo: nil, bookmarkDataIsStale: &isSSNField)
        print(videoURL)
    } catch {
        print(error)
    }

}

在应用程序被杀死后请求使用通过 UIImagePickerController 选取的视频文件的权限

Requesting permission to use a video file that is picked with UIImagePickerController after app is killed

permissions

uiimagepickercontroller

swift

swift4