Converting WriteableBitmap to stream on WP8

Question

How can I convert a WriteableBitmap to stream on WP8 platform?

Final goal is to dump the image output produced by native code to the CameraRoll library using SavePictureToCameraRoll(filename, stream)

Answer 1

You can encode your bitmap to stream with WritableBitmap.SaveJpeg method and use this stream as a parameter to MediaLibrary.SavePictureToCameraRoll.
Note: before calling MediaLibrary.SavePictureToCameraRoll don't forget to set the stream position to 0 if you're using a MemoryStream. Like this:

var wb = new WriteableBitmap(bitmap);
var fileStream = new MemoryStream();
wb.SaveJpeg(fileStream, wb.PixelWidth, wb.PixelHeight, 100, 100);
fileStream.Seek(0, SeekOrigin.Begin);

var m = new MediaLibrary();
m.SavePictureToCameraRoll("test", fileStream);