Set image from bitmap

Question

Image image = new Image ();
Bitmap bitmap = Bitmap.CreateBitmap (200, 100, Bitmap.Config.Argb8888);
Canvas canvas = new Canvas(bitmap);

var paint = new Paint();
paint.Color = Android.Graphics.Color.Red;
paint.SetStyle(Paint.Style.Fill);

Rect rect = new Rect(0, 0, 200, 100);
canvas.DrawRect(rect, paint);

Android.Widget.ImageView contains method SetImageBitmap.
What the best way to set Xamarin.Forms.Image from my bitmap?

Answer 1

Convert the Bitmap to byte[] via http://forums.xamarin.com/discussion/5950/how-to-convert-from-bitmap-to-byte-without-bitmap-compress

There are two solutions mentioned.

1. var byteArray = ByteBuffer.Allocate(bitmap.ByteCount);
   bitmap.CopyPixelsToBuffer(byteArray);
   byte[] bytes = byteArray.ToArray<byte>();
   return bytes;
   

2. (in case first solution is still broken)

   ByteBuffer buffer = ByteBuffer.Allocate(bitmap.ByteCount);
   bitmap.CopyPixelsToBuffer(buffer);
   buffer.Rewind();
   
   IntPtr classHandle = JNIEnv.FindClass("java/nio/ByteBuffer");
   IntPtr methodId = JNIEnv.GetMethodID(classHandle, "array", "()[B");
   IntPtr resultHandle = JNIEnv.CallObjectMethod(buffer.Handle, methodId);
   byte[] byteArray = JNIEnv.GetArray<byte>(resultHandle);
   JNIEnv.DeleteLocalRef(resultHandle);
   

And then use

var image = new Image();
image.Source = ImageSource.FromStream(() => new MemoryStream(byteArray));

to create an Image.