Download and Save image in Pictures Library through Windows 8 Metro XAML App

Question

I am trying to develop a simple Windows 8 Metro app which simply downloads an image file from a given URL (say http://sample.com/foo.jpg) and then save it to Pictures Librar

Answer 1

Here's some rough code that I believe accomplishes what you want. It assumes you have two image controls (Image1 and Image2) and that you have the Pictures Library capability checked in the manifest. Take a look at the XAML images sample as well

        Uri uri = new Uri("http://www.picsimages.net/photo/lebron-james/lebron-james_1312647633.jpg");
        var fileName = Guid.NewGuid().ToString() + ".jpg";

        // download pic
        var bitmapImage = new BitmapImage();
        var httpClient = new HttpClient();
        var httpResponse = await httpClient.GetAsync(uri);
        byte[] b = await httpResponse.Content.ReadAsByteArrayAsync();

        // create a new in memory stream and datawriter
        using (var stream = new InMemoryRandomAccessStream())
        {
            using (DataWriter dw = new DataWriter(stream))
            {
                // write the raw bytes and store
                dw.WriteBytes(b);
                await dw.StoreAsync();

                // set the image source
                stream.Seek(0);
                bitmapImage.SetSource(stream);

                // set image in first control
                Image1.Source = bitmapImage;

                // write to pictures library
                var storageFile = await KnownFolders.PicturesLibrary.CreateFileAsync(
                    fileName, 
                    CreationCollisionOption.ReplaceExisting);

                using (var storageStream = await storageFile.OpenAsync(FileAccessMode.ReadWrite))
                {
                    await RandomAccessStream.CopyAndCloseAsync(stream.GetInputStreamAt(0), storageStream.GetOutputStreamAt(0));
                }
            }
        }

        // read from pictures library
        var pictureFile = await KnownFolders.PicturesLibrary.GetFileAsync(fileName);
        using ( var pictureStream = await pictureFile.OpenAsync(FileAccessMode.Read) )
        {
            bitmapImage.SetSource(pictureStream);
        }
        Image2.Source = bitmapImage;
    }