objective-c - (IOS 10) RequestAVAssetForVideo 结果资产 = nil

Question

RequestAVAssetForVideo 结果一直为零：

• iOS 10（仅限）（iOS 11 运行良好）
• 当前 iPhone 上未录制的视频
• 存储在照片库中的视频
• 请求的localIdentifier = 1BF03030-1CB7-49ED-9314-D0B8D1C34D72/L0/001

资产Url = nil

PHAsset* 资产 = [PHAsset fetchAssetsWithLocalIdentifiers:@[file.localIdentifier] options:nil].firstObject;

[[PHImageManager defaultManager] requestAVAssetForVideo:asset options:nil resultHandler:^(AVAsset *avAsset, AVAudioMix *audioMix, NSDictionary *info) {

   //here asset in nil! IOS 10 only, IOS 11 works fine
   AVURLAsset * assetUrl = (AVURLAsset*)avAsset;


}];