iOS 获取摄像头当前方向

在做二维码扫描和直播获取视频流的过程中，可能会用到

AVCaptureDevice

AVCaptureVideoPreviewLayer

AVCaptureSession

这几个参数，其中

1、定义显示layer

var preview:AVCaptureVideoPreviewLayer! = nil

2、获取摄像头方向

self.preview = AVCaptureVideoPreviewLayer(session: self.session)
self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill
self.preview.connection.videoOrientation = self.getDeviceDirection()

重点就是这里getDeviceDirection方法，这里我的做法就是根据当前状态栏方向判断摄像头方向。

代码实现：

  /// 获取当前摄像头方向
    ///
    /// - Returns: <#return value description#>
    func getDeviceDirection() -> AVCaptureVideoOrientation{
        switch UIApplication.shared.statusBarOrientation {
        case .landscapeLeft:
            return AVCaptureVideoOrientation.landscapeLeft
        case .landscapeRight:
            return AVCaptureVideoOrientation.landscapeRight
        case .portrait:
            return AVCaptureVideoOrientation.portrait
        case .portraitUpsideDown:
            return AVCaptureVideoOrientation.portraitUpsideDown
        default:
            return AVCaptureVideoOrientation.landscapeRight
        }
    }