private void clickCancelRotate(object sender, RoutedEventArgs e)
        {
            btRotateImage.Visibility = Visibility.Visible;
            // btCropImage.Visibility = Visibility.Visible;

            btAcceptRotate.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
            btRotate.Visibility       = Windows.UI.Xaml.Visibility.Collapsed;
            btCancel.Visibility       = Windows.UI.Xaml.Visibility.Collapsed;

            begin.Value = 0;
            end.Value   = 0;
            HieuUngXoay90.Begin();
        }
        private async void clickAcceptRotateImage(object sender, RoutedEventArgs e)
        {
            btRotateImage.Visibility = Visibility.Visible;
            //  btCropImage.Visibility = Visibility.Visible;

            btAcceptRotate.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
            btRotate.Visibility       = Windows.UI.Xaml.Visibility.Collapsed;
            btCancel.Visibility       = Windows.UI.Xaml.Visibility.Collapsed;


            await App.photo.ApplyRotationFilterAsync(-begin.Value);

            Debug.WriteLine("Thưc hiện quay: " + (-begin.Value));
            App.photo.IsSaved = false;
            begin.Value       = 0;
            end.Value         = 0;
            xImage.Source     = App.photo.OriginalBitmap;

            HieuUngXoay90.Begin();
        }
        private void clickRotate(object sender, RoutedEventArgs e)
        {
            Debug.WriteLine("Trước:\nh = " + xImage.ActualHeight + "\nw = " + xImage.ActualWidth);

            HieuUngXoay90.Begin();
        }