private Task <MediaFile> GetMediaAsync(UIImagePickerControllerSourceType sourceType, string mediaType, CameraFacingDirection cameraFacingDirection, StoreMediaOptions options = null) { var window = UIApplication.SharedApplication.KeyWindow; if (window == null) { throw new InvalidOperationException("There's no current active window"); } var viewController = window.RootViewController; if (viewController == null) { window = UIApplication.SharedApplication.Windows.OrderByDescending(w => w.WindowLevel).FirstOrDefault(w => w.RootViewController != null); if (window == null) { throw new InvalidOperationException("Could not find current view controller"); } else { viewController = window.RootViewController; } } while (viewController.PresentedViewController != null) { viewController = viewController.PresentedViewController; } MediaPickerDelegate ndelegate = new MediaPickerDelegate(viewController, sourceType, options); var od = Interlocked.CompareExchange(ref this.pickerDelegate, ndelegate, null); if (od != null) { throw new InvalidOperationException("Only one operation can be active at at time"); } var picker = SetupController(ndelegate, sourceType, mediaType, cameraFacingDirection, options); if (UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad && sourceType == UIImagePickerControllerSourceType.PhotoLibrary) { ndelegate.Popover = new UIPopoverController(picker); ndelegate.Popover.Delegate = new MediaPickerPopoverDelegate(ndelegate, picker); ndelegate.DisplayPopover(); } else { viewController.PresentViewController(picker, true, null); } return(ndelegate.Task.ContinueWith( t => { if (this.popover != null) { this.popover.Dispose(); this.popover = null; } Interlocked.Exchange(ref this.pickerDelegate, null); return t; }).Unwrap()); }