如何在xamarin Android中裁剪旋转过的图像？

using Android.App;
using Android.Content;
using Android.Graphics;
using Android.OS;
using Android.Widget;

namespace XamarinAndroidImageProcessing
{
    [Activity(Label = "ImageProcessingActivity")]
    public class ImageProcessingActivity : Activity
    {
        private ImageView imageView;

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.activity_image_processing);

            imageView = FindViewById<ImageView>(Resource.Id.image_view);

            // 加载图像
            Bitmap originalBitmap = BitmapFactory.DecodeResource(Resources, Resource.Drawable.sample_image);
            
            // 旋转图像
            Matrix matrix = new Matrix();
            matrix.PostRotate(90); // 设置旋转角度
            Bitmap rotatedBitmap = Bitmap.CreateBitmap(originalBitmap, 0, 0, originalBitmap.Width, originalBitmap.Height, matrix, true);
            
            // 裁剪图像
            int cropWidth = 200;
            int cropHeight = 200;
            int cropX = rotatedBitmap.Width / 2 - cropWidth / 2;
            int cropY = rotatedBitmap.Height / 2 - cropHeight / 2;
            Rect cropRect = new Rect(cropX, cropY, cropX + cropWidth, cropY + cropHeight);
            Bitmap croppedBitmap = Bitmap.CreateBitmap(rotatedBitmap, cropRect.Left, cropRect.Top, cropRect.Width(), cropRect.Height());

            // 显示裁剪后的图像
            imageView.SetImageBitmap(croppedBitmap);
        }
    }
}