C# Windows 8 Store (Metro, WinRT) Byte array to BitmapImage

Question

I am working on a Windows 8 Metro app that applies filters to images. I have a web version of the app and wanted to port it. But as we all know WinRT doesn\'t have all the g

Answer 1

this is my first answer..hope it will help.

I had the exact same problem and I spand more then 6 hours trying to figur this out. this is what i came up with: what you said was right. there are 2 waye to convert image to byteArray:

First aproach(yours)

        public async Task<byte[]> ImageFileToByteArrayAsync(StorageFile file)
    {
        IRandomAccessStream stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
        BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream);
        PixelDataProvider pixelData = await decoder.GetPixelDataAsync();
        return pixelData.DetachPixelData();
    }

Second aproach

        public async Task<byte[]> ImageFileToByteArrayAsync(StorageFile file)
    {
        var inputStream = await file.OpenSequentialReadAsync();
        var readStream = inputStream.AsStreamForRead();
        var buffer = new byte[readStream.Length];
        await readStream.ReadAsync(buffer, 0, buffer.Length);
        return buffer;
    }

if youll use the second aproach to decode the pic, with no Pixel, this converter will work:

public class ByteArrayToImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        if (value == null || !(value is byte[]))
            return null;

        using (InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream())
        {
            using (DataWriter writer = new DataWriter(stream.GetOutputStreamAt(0)))
            {
                writer.WriteBytes((byte[])value);
                writer.StoreAsync().GetResults();
            }
            BitmapImage image = new BitmapImage();
            image.SetSource(stream);
            return image;
        }
    }
    public object ConvertBack(object value, Type targetType, object parameter, string language)                                                                         
    {
        throw new NotImplementedException();
    }

for the first aproach youll need to work with WriteableBitmap as you said.

Answer 2

This is working for me,

    private async Task<BitmapImage> ByteArrayToBitmapImage(byte[] byteArray)
    {
        var bitmapImage = new BitmapImage();

        var stream = new InMemoryRandomAccessStream();
        await stream.WriteAsync(byteArray.AsBuffer());
        stream.Seek(0);

        bitmapImage.SetSource(stream);
        return bitmapImage;
    }