iOS 6中不推荐使用方向

Question

Looks like orientation for avcapturevideopreviewlayer has been depreciated in iOS 6. Anyone know the new code? Here is my current (depreciated) code:

[self setPreviewLayer:[[AVCaptureVideoPreviewLayer alloc] initWithSession:[self captureSession]]];
[[self previewLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
previewLayer.orientation = UIInterfaceOrientationLandscapeRight;

Answer 1

Did you check the documentation? It's only one line:

The layer's orientation. (Deprecated in iOS 6.0. Use videoOrientation (AVCaptureConnection) instead.)

so use:

[[AVCaptureVideoPreviewLayer connection] setVideoOrientation: AVCaptureVideoOrientationLandscapeRight];

or

AVCaptureVideoPreviewLayer.connection.videoOrientation= AVCaptureVideoOrientationLandscapeRight;

Answer 2

I tried to use videoOrientation(AVCaptureConnection) instead of the deprecated orientation(AVCaptureVideoPreviewLayer), but it did not rotate the video preview anymore.

I replaced this:

AVCaptureVideoPreviewLayer *previewLayer = ...;
previewLayer.orientation = AVCaptureVideoOrientationLandscapeRight;

With this:

AVCaptureVideoPreviewLayer *previewLayer = ...;
previewLayer.connection.videoOrientation = AVCaptureVideoOrientationLandscapeRight;

But it did not rotate the video preview. The problem was that I added and modified the AVCaptureVideoPreviewLayer before I added the AVCaptureDeviceInput to my AVCaptureSession. Therefore the connection of my AVCaptureVideoPreviewLayer was null. The solution was to add the AVCaptureVideoPreviewLayer after I added the AVCaptureDeviceInput to my AVCaptureSession.

Answer 3

Just like @Nikolai posted, use the AVCaptureVideoPreviewLayer's connection's videoOrientation property instead.

(The reason I am posting this again is because his code may be a bit confusing since it looks like connection is a class method. Hopefully this example makes it clear.)

Replace the following:

AVCaptureVideoPreviewLayer *previewLayer = ...;
previewLayer.orientation = UIInterfaceOrientationLandscapeRight;

With:

AVCaptureVideoPreviewLayer *previewLayer = ...;
previewLayer.connection.videoOrientation = AVCaptureVideoOrientationLandscapeRight;