ios - 强制保存的图像与iCloud Photo Stream同步

Question

我有一个可定期拍摄图像的应用程序，我希望在拍摄图像后立即将其上传到iCloud Photo Stream。

看来需要满足某些条件才能使它起作用。它似乎仅在运行iOS 8时有效，该设备已连接至无线设备，并使用UIImagePickerController至少拍摄了一次图片(而不是AVCapture)。出现时，似乎UIImagePickerController更改了一些系统设置，从而允许随后将图像自动上载到iCloud Photo Stream。如果我仅使用AVCapture拍摄照片，它将无法工作。我已确认在iCloud设置中启用了“上传到我的照片流”，并且存在 Activity 的无线连接。

这是用于保存从UIImagePickerController获得的图像的方法:

- (void)saveImage : (UIImage *)image {
    // Add image to the photo library
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        PHAssetChangeRequest *assetChangeRequest =
        [PHAssetChangeRequest creationRequestForAssetFromImage:image];
    } completionHandler:^(BOOL success, NSError *error) {
        if (!success)
            NSLog(@"Error creating asset: %@", error);
    }];
}

在装有iOS 8的iPad上运行时，以下是我在设备系统日志中看到的条目:

Oct 22 21:11:06 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Submitting 1 asset collections for publication.
Oct 22 21:11:06 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...
Oct 22 21:11:10 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx uploading 1 assets...
Oct 22 21:11:11 iPad mstreamd[14409] <Notice>: (Note ) PS: Received push notification for invitations topic: com.apple.mediastream.subscription.push userInfo: {
        r = xxxxxxxx;
    }
Oct 22 21:11:11 iPad mstreamd[14409] <Notice>: (Note ) PS: <MSIOSMediaStreamDaemon: 0x1662ad80>: Push notification received for My Photo Stream with targetPersonID xxxxxxxx.
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x1666fae0>: Plugged in to external power. Allowing file transfers.
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x1666fae0>: Push received. Allowing file transfers to continue for 60.00 seconds
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) PS: MSSubscriber - xxxxxxxx Found 1 new asset collections.
Oct 22 21:11:13 iPad assetsd[11536] <Warning>: Unable to open file to save extended attributes (No such file or directory).

在装有iOS 9.1的iPhone上运行时，我有类似的日志条目，除了关于缓存服务器的其他警告/错误消息以粗体显示之外:

Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Submitting 1 asset collections for publication.
Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...
**Oct 25 22:35:28 iPhone AssetCacheLocatorService[1658] <Warning>: #df99fdd0 [I:AssetCacheLocatorService.queue] found no caching servers**
Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx uploading 1 assets...
**Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Error) mmcs: __mmcs_proxy_locator_exists_block_invoke:167 might have caching server returned with error: Error Domain=NSPOSIXErrorDomain Code=60 "Operation timed out" UserInfo={com.apple.AssetCacheLocator.tag=#1963bd2d, NSLocalizedDescription=quick miss requested}**
**Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...**
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: Received push notification for invitations topic: com.apple.mediastream.subscription.push userInfo: {
        r = xxxxxxxx;
    }
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: <MSIOSMediaStreamDaemon: 0x157e0c530>: Push notification received for My Photo Stream with targetPersonID xxxxxxxx.
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x157e84410>: Plugged in to external power. Allowing file transfers.
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x157e84410>: Push received. Allowing file transfers to continue for 60.00 seconds
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSSubscriber - xxxxxxxx Found 1 new asset collections.
Oct 25 22:35:30 iPhone assetsd[1624] <Warning>: Unable to open file to save extended attributes (No such file or directory).

在这种情况下，使用iOS 9时，当我的应用程序处于 Activity 状态时，不会上传图像，仅在应用程序进入后台时才上传图像。

我怀疑该问题是由于1.某些系统设置仅在iOS8中通过UIImagePickerController的显示被激活的，或者2.日志条目所建议的在iOS 9中缓存服务器的某些问题。

任何人都知道发生了什么事吗？任何想法将不胜感激!谢谢!

Answer 1

我想我已经找到了解决方案。看来，如果正在运行AVCaptureSession，则iCloud Photo Stream将不会同步。调用stopRunning方法(如下所示)似乎可以解决问题:

[self.cameraSession stopRunning];