AVCam.CameraViewController.ChangeCamera C# (CSharp) Method

		void ChangeCamera (UIButton cameraButton)
		{
			cameraButton.Enabled = false;
			RecordButton.Enabled = false;
			PhotoButton.Enabled = false;
			LivePhotoModeButton.Enabled = false;
			CaptureModeControl.Enabled = false;

			sessionQueue.DispatchAsync (() => {
				AVCaptureDevice currentVideoDevice = videoDeviceInput.Device;
				AVCaptureDevicePosition currentPosition = currentVideoDevice.Position;

			AVCaptureDevicePosition preferredPosition = 0;
			AVCaptureDeviceType preferredDeviceType = 0;

				switch (currentPosition) {
				case AVCaptureDevicePosition.Unspecified:
				case AVCaptureDevicePosition.Front:
					preferredPosition = AVCaptureDevicePosition.Back;
					preferredDeviceType = AVCaptureDeviceType.BuiltInDuoCamera;
					break;

				case AVCaptureDevicePosition.Back:
					preferredPosition = AVCaptureDevicePosition.Front;
					preferredDeviceType = AVCaptureDeviceType.BuiltInWideAngleCamera;
					break;
				}

				var devices = videoDeviceDiscoverySession.Devices;
				AVCaptureDevice newVideoDevice = null;

				// First, look for a device with both the preferred position and device type. Otherwise, look for a device with only the preferred position.
				newVideoDevice = devices.FirstOrDefault (d => d.Position == preferredPosition && d.DeviceType == preferredDeviceType)
							  ?? devices.FirstOrDefault (d => d.Position == preferredPosition);

				if (newVideoDevice != null) {
					NSError error;
					var input = AVCaptureDeviceInput.FromDevice (newVideoDevice, out error);
					if (error == null) {
						session.BeginConfiguration ();

						// Remove the existing device input first, since using the front and back camera simultaneously is not supported.
						session.RemoveInput (videoDeviceInput);

						if (session.CanAddInput (input)) {
							subjectSubscriber?.Dispose ();
							subjectSubscriber = NSNotificationCenter.DefaultCenter.AddObserver (AVCaptureDevice.SubjectAreaDidChangeNotification, SubjectAreaDidChange, input.Device);
							session.AddInput (input);
							videoDeviceInput = input;
						} else {
							session.AddInput (videoDeviceInput);
						}

						var connection = MovieFileOutput?.ConnectionFromMediaType (AVMediaType.Video);
						if (connection != null) {
							if (connection.SupportsVideoStabilization)
								connection.PreferredVideoStabilizationMode = AVCaptureVideoStabilizationMode.Auto;
						}

						// Set Live Photo capture enabled if it is supported.When changing cameras, the
						// IsLivePhotoCaptureEnabled property of the AVCapturePhotoOutput gets set to false when
						// a video device is disconnected from the session.After the new video device is
						// added to the session, re - enable Live Photo capture on the AVCapturePhotoOutput if it is supported.
						photoOutput.IsLivePhotoCaptureEnabled = photoOutput.IsLivePhotoCaptureSupported;
						session.CommitConfiguration ();
					}
				}

				DispatchQueue.MainQueue.DispatchAsync (() => {
					CameraButton.Enabled = true;
					RecordButton.Enabled = MovieFileOutput != null;
					PhotoButton.Enabled = true;
					LivePhotoModeButton.Enabled = true;
					CaptureModeControl.Enabled = true;
				});
			});
		}