获取新创建的资产的URL,iOS 9样式

Question

ALAssetsLibrary这些天已被弃用,但几乎所有关于SO的例子仍在使用它.为了我的目标,我需要知道添加到照片库的视频的URL,以便我可以将视频分享到Instagram应用程序(这是Instagram接受视频的唯一方式).URL应该以"assets-library:// ..."开头

这很简单ALAssetsLibrary:

ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library writeVideoAtPathToSavedPhotosAlbum:videoFilePath completionBlock:^(NSURL *assetURL, NSError *error) {  // ...

在上面,URL作为参数传递给完成块.但是iOS 9与PHPhotoLibrary类和performChanges方法的兼容方式呢？

var videoAssetPlaceholder:PHObjectPlaceholder!  // property

// ...

let videoURL = NSBundle.mainBundle().URLForResource("Video_.mp4", withExtension: nil)!

let photoLibrary = PHPhotoLibrary.sharedPhotoLibrary()
photoLibrary.performChanges({
    let request = PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(videoURL)
    self.videoAssetPlaceholder = request?.placeholderForCreatedAsset
},
completionHandler: { success, error in
    if success
    {
        // The URL of the video asset?
    }
})

Answer 1

这就是我最终得到的结果:

let videoURL = NSBundle.mainBundle().URLForResource("Video_.mp4", withExtension: nil)!

let photoLibrary = PHPhotoLibrary.sharedPhotoLibrary()
var videoAssetPlaceholder:PHObjectPlaceholder!
photoLibrary.performChanges({
    let request = PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(videoURL)
    videoAssetPlaceholder = request!.placeholderForCreatedAsset
},
completionHandler: { success, error in
    if success {
        let localID = videoAssetPlaceholder.localIdentifier
        let assetID =
            localID.stringByReplacingOccurrencesOfString(
                "/.*", withString: "",
                options: NSStringCompareOptions.RegularExpressionSearch, range: nil)
        let ext = "mp4"
        let assetURLStr =
            "assets-library://asset/asset.\(ext)?id=\(assetID)&ext=\(ext)"

        // Do something with assetURLStr
    }
})

Answer 2

很好的答案和伪，谢谢德斯蒙德。

这是更新的答案：

雨燕3

var assetPlaceholder: PHObjectPlaceholder!
    PHPhotoLibrary.shared().performChanges({
        let assetRequest = PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL as URL!)
        assetPlaceholder = assetRequest?.placeholderForCreatedAsset
    }, completionHandler: { (success, error) in
        if success {
            let localID = assetPlaceholder.localIdentifier
            let assetID = localID.replacingOccurrences(of: "/.*", with: "", options: NSString.CompareOptions.regularExpression, range: nil)
            let ext = "mp4"
            let assetURLStr = "assets-library://asset/asset.\(ext)?id=\(assetID)&ext=\(ext)"

            // Do what you want with your assetURLStr
        } else {
            if let errorMessage = error?.localizedDescription {
                print(errorMessage)
            }
        }
    })

更进一步

虽然目前这工作得很好，但如果没有这个“手动”解决方案，有人知道一种“更干净”的方式来获取这个“资产库”URL吗？

我发现这个有趣的线程，但它只提供了一个“file:///var/...” URL