Xamarin Android软件渲染不支持硬件位图

如何解决Xamarin Android软件渲染不支持硬件位图

我有一个需要拍照并将其转换为灰度的应用程序。它曾经在Android 9.0下运行。我升级到Android 11.0，显然有一个重大变化。我创建了一个独立的活动来重现该问题：

using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Graphics;
using Android.OS;
using Android.Provider;
using Android.Support.Design.Widget;
using Android.Support.V7.App;
using Android.Views;
using Android.Widget;
using System;

namespace BitmapRenderIssue
{
    [Activity(Label = "@string/app_name",Theme = "@style/AppTheme.NoActionBar",MainLauncher = true)]
    public class MainActivity : AppCompatActivity
    {
        private const int CAPTURE_PHOTO = 100;
        private static Android.Net.Uri ImageUri;
        ImageView imageView1;
        private static Bitmap CurrImage;

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

            Android.Support.V7.Widget.Toolbar toolbar = FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
            SetSupportActionBar(toolbar);

            imageView1 = FindViewById<ImageView>(Resource.Id.imageView1);
            FloatingActionButton fab = FindViewById<FloatingActionButton>(Resource.Id.fab);
            fab.Click += FabOnClick;
        }

        public override bool OnCreateOptionsMenu(IMenu menu)
        {
            MenuInflater.Inflate(Resource.Menu.menu_main,menu);
            return true;
        }

        public override bool OnOptionsItemSelected(IMenuItem item)
        {
            int id = item.ItemId;
            if (id == Resource.Id.action_settings)
            {
                return true;
            }

            return base.OnOptionsItemSelected(item);
        }

        private void FabOnClick(object sender,EventArgs eventArgs)
        {
            TakePicture();
        }

        public bool isCameraPermissionGranted()
        {
            if (Build.VERSION.SdkInt >= BuildVersionCodes.M)
            {
                if (CheckSelfPermission(Android.Manifest.Permission.Camera)
                        == Permission.Granted)
                {
                    return true;
                }
                else
                {
                    RequestPermissions(new String[] { Android.Manifest.Permission.Camera },1);
                    return false;
                }
            }
            else
            { //permission is automatically granted on sdk<23 upon installation
                return true;
            }
        }

        public override void OnRequestPermissionsResult(int requestCode,string[] permissions,Permission[] grantResults)
        {
            base.OnRequestPermissionsResult(requestCode,permissions,grantResults);
            if (grantResults[0] == Permission.Granted)
            {
                CapturePhoto();
            }
        }

        public void CapturePhoto()
        {
            ImageUri = ContentResolver.Insert(MediaStore.Images.Media.ExternalContentUri,new ContentValues());
            var i = new Intent(MediaStore.ActionImageCapture);
            i.PutExtra(MediaStore.ExtraOutput,ImageUri);
            StartActivityForResult(i,CAPTURE_PHOTO);
        }

        public void TakePicture()
        {

            if (isCameraPermissionGranted())
                CapturePhoto();
        }

        protected override void OnActivityResult(int requestCode,Result resultCode,Intent data)
        {
            if (resultCode == Result.Ok && requestCode == CAPTURE_PHOTO && ImageUri != null)
            {
                Android.Util.Log.Info("CameraScanning","Getting Picture");

                var src = ImageDecoder.CreateSource(ContentResolver,ImageUri);
                Bitmap img = ImageDecoder.DecodeBitmap(src);

                CurrImage = ImageProcessing.Grayscale_ColorMatrixColorFilter(img);

                img.Recycle();
                img.Dispose();

                imageView1.SetImageBitmap(CurrImage);

                Java.IO.File xFile = new Java.IO.File(ImageUri.Path);
                if (xFile.Exists())
                    xFile.Delete();
                ImageUri = null;
            }
        }

    }
}

这是有问题的函数的代码：

public static class ImageProcessing
{
    public static Bitmap Grayscale_ColorMatrixColorFilter(Bitmap src)
    {
        int width = src.Width;
        int height = src.Height;

        Bitmap dest = Bitmap.CreateBitmap(width,height,Bitmap.Config.Rgb565);

        Canvas canvas = new Canvas(dest);

        Paint paint = new Paint();
        ColorMatrix colorMatrix = new ColorMatrix();
        colorMatrix.SetSaturation(0); //value of 0 maps the color to gray-scale
        ColorMatrixColorFilter filter = new ColorMatrixColorFilter(colorMatrix);
        paint.SetColorFilter(filter);
        canvas.DrawBitmap(src,paint);

        return dest;
    }
}

此函数在对canvas的调用上引发“软件渲染不支持硬件位图”。DrawBitmap（src，0，0，paint）;

我已经尝试了Software rendering doesn't support hardware bitmap in Oreo

中找到的所有hardwareAccelerated选项

我创建了一个具有Visual Studio项目的存储库，该项目将重现此错误。只需运行该应用程序即可。单击浮动操作按钮。拍摄照片。点击确定。错误会发生。

https://github.com/JimWilcox3/BitmapRenderIssue

谢谢， 吉姆

解决方法

好的，这就是我所想的。在活动中，我添加了一个新类来充当OnHeaderDecoded事件的侦听器。在此类中，我将MutableRequired = true设置。

    private class OnHeaderDecodedListener : Java.Lang.Object,IOnHeaderDecodedListener
    {

        public void OnHeaderDecoded(ImageDecoder decoder,ImageInfo info,Source source)
        {
            decoder.MutableRequired = true;
        }

    }

然后在OnActivityResult中，我更改了

Bitmap img = ImageDecoder.DecodeBitmap(src); 

到

Bitmap img = ImageDecoder.DecodeBitmap(src,new OnHeaderDecodedListener());

这导致它创建了不是硬件位图的可变位图。

干杯， 吉姆