AVCapture - AVCaptureVideoPreviewLayer 横屏方向问题

iPad横屏应用 时 图像旋转了90度

AVCaptureVideoPreviewLayer * layer = [AVCaptureVideoPreviewLayer layerWithSession:session];
    layer.videoGravity=AVLayerVideoGravityResizeAspectFill;
    UIInterfaceOrientation interfaceOrientation = [UIApplication sharedApplication].statusBarOrientation;
    if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft){
         layer.orientation = UIInterfaceOrientationLandscapeLeft;
    } else {
         layer.orientation = AVCaptureVideoOrientationLandscapeRight;
    }

这样修改时，图像恢复正常，但是有个警告

用layer 的connection 的 videoOrientation属性

if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft){
         layer.connection.videoOrientation = UIInterfaceOrientationLandscapeLeft;
    } else {
         layer.connection.videoOrientation = AVCaptureVideoOrientationLandscapeRight;
    }