c# - How save BitmapImage WinRT

Question

I have BitmapImage:

BitmapImage image = new BitmapImage();
image.SetSource(memStream);

I want to save the image to the disk to see in the future. I can not find a work example of how to do this? The second question. I need to get the color of a pixel (like: Color cl=image.GetColorPixel(X,Y)), how can I do that? Thank you!

Answer 1

Here's a code I found sometime ago in the web. I'm not sure, but if I rember right it was from the sdk samples or a winrt blog

It all comes down to the WritabelBitmap Image ( like the other already posted), create a decoder and push it to the stream.

  /// <summary>
        /// 
        /// </summary>
        /// <param name="writeableBitmap"></param>
        /// <param name="outputFile"></param>
        /// <param name="encoderId"></param>
        /// <returns></returns>
        public static async Task SaveToFile(
            this WriteableBitmap writeableBitmap,
            IStorageFile outputFile,
            Guid encoderId)
        {
            try
            {
                Stream stream = writeableBitmap.PixelBuffer.AsStream();
                byte[] pixels = new byte[(uint)stream.Length];
                await stream.ReadAsync(pixels, 0, pixels.Length);

                using (var writeStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
                {
                    var encoder = await BitmapEncoder.CreateAsync(encoderId, writeStream);
                    encoder.SetPixelData(
                        BitmapPixelFormat.Bgra8,
                        BitmapAlphaMode.Premultiplied,
                        (uint)writeableBitmap.PixelWidth,
                        (uint)writeableBitmap.PixelHeight,
                        96,
                        96,
                        pixels);
                    await encoder.FlushAsync();

                    using (var outputStream = writeStream.GetOutputStreamAt(0))
                    {
                        await outputStream.FlushAsync();
                    }
                }
            }
            catch (Exception ex)
            {
                string s = ex.ToString();
            }
        }