AVCam.CameraViewController.UpdateDeviceFocus C# (CSharp) Method

		void UpdateDeviceFocus (AVCaptureFocusMode focusMode, AVCaptureExposureMode exposureMode, CGPoint point, bool monitorSubjectAreaChange)
		{
			sessionQueue.DispatchAsync (() => {
				var device = videoDeviceInput?.Device;
				if (device == null)
					return;

				NSError error;
				if (device.LockForConfiguration (out error)) {
					// Setting (Focus/Exposure)PointOfInterest alone does not initiate a (focus/exposure) operation.
					// Set (Focus/Exposure)Mode to apply the new point of interest.
					if (device.FocusPointOfInterestSupported && device.IsFocusModeSupported (focusMode)) {
						device.FocusPointOfInterest = point;
						device.FocusMode = focusMode;
					}
					if (device.ExposurePointOfInterestSupported && device.IsExposureModeSupported (exposureMode)) {
						device.ExposurePointOfInterest = point;
						device.ExposureMode = exposureMode;
					}
					device.SubjectAreaChangeMonitoringEnabled = monitorSubjectAreaChange;
					device.UnlockForConfiguration ();
				} else {
					Console.WriteLine ($"Could not lock device for configuration: {error.LocalizedDescription}");
				}
			});
		}