AndroidApp.BitmapHelpers.GetAndRotateBitmap C# (CSharp) Method

        public static Bitmap GetAndRotateBitmap(string fileName)
        {
            Bitmap bitmap = BitmapFactory.DecodeFile(fileName);

            // Images are being saved in landscape, so rotate them back to portrait if they were taken in portrait
            // See https://forums.xamarin.com/discussion/5409/photo-being-saved-in-landscape-not-portrait
            // See http://developer.android.com/reference/android/media/ExifInterface.html
            using (Matrix mtx = new Matrix())
            {
                if (Android.OS.Build.Product.Contains("Emulator"))
                {
                    mtx.PreRotate(90);
                }
                else
                {
                    ExifInterface exif = new ExifInterface(fileName);
                    var orientation = (Orientation)exif.GetAttributeInt(ExifInterface.TagOrientation, (int)Orientation.Normal);

                    //TODO : handle FlipHorizontal, FlipVertical, Transpose and Transverse
                    switch (orientation)
                    {
                        case Orientation.Rotate90:
                            mtx.PreRotate(90);
                            break;
                        case Orientation.Rotate180:
                            mtx.PreRotate(180);
                            break;
                        case Orientation.Rotate270:
                            mtx.PreRotate(270);
                            break;
                        case Orientation.Normal:
                            // Normal, do nothing
                            break;
                        default:
                            break;
                    }
                }

                if (mtx != null)
                    bitmap = Bitmap.CreateBitmap(bitmap, 0, 0, bitmap.Width, bitmap.Height, mtx, false);
            }

            return bitmap;
        }
    }

        protected override async void OnActivityResult(int requestCode, Result resultCode, Intent data)
        {
            base.OnActivityResult(requestCode, resultCode, data);

            try
            {
                //Get the bitmap with the right rotation
                _bitmap = BitmapHelpers.GetAndRotateBitmap(_file.Path);

                using (System.IO.MemoryStream stream = new System.IO.MemoryStream())
                {
                    //Get a stream
                    _bitmap.Compress(Bitmap.CompressFormat.Jpeg, 100, stream);
                    stream.Seek(0, System.IO.SeekOrigin.Begin);

                    //Get and display the happiness score
                    float result = await Core.GetAverageHappinessScore(stream);

                    _resultTextView.Text = Core.GetHappinessMessage(result);
                }

                //Display the image
                _imageView.SetImageBitmap(_bitmap);
            }
            catch (Exception ex)
            {
                _resultTextView.Text = ex.Message;
            }
            finally
            {
                _pictureButton.Text = "Reset";
                _isCaptureMode      = false;
            }
        }