private async Task updateUI(MyFilesModel item)
{
if (!item.ImageLoaded)
{
item.Bitmap = await MyFilesController.GetImage(item, (int)Window.Current.Bounds.Width);
item.ImageLoaded = true;
}
}
/// <summary>
/// Retrieves a binary image and resizes it accordingly
/// </summary>
/// <param name="item">MyFilesModel object</param>
/// <returns>resized BitmapSource</returns>
public static async Task<BitmapSource> GetImage(MyFilesModel item, int w)
{
BitmapImage img = new BitmapImage();
//ensure client created
var client = await EnsureClient();
//get the file stream
using (Stream stream = await client.Files.GetById(item.Id).ToFile().DownloadAsync())
{
using (var memStream = new MemoryStream())
{
await stream.CopyToAsync(memStream);
memStream.Position = 0;
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(memStream.AsRandomAccessStream());
using (InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream())
{
//first get original specs so we can scale the resize best
BitmapEncoder enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
await enc.FlushAsync();
BitmapImage original = new BitmapImage();
original.SetSource(ras);
int height = original.PixelHeight;
int width = original.PixelWidth;
//rewind and take a second pass...this time resizing
ras.Seek(0);
enc = await BitmapEncoder.CreateForTranscodingAsync(ras, decoder);
enc.BitmapTransform.ScaledHeight = (uint)(((double)height / (double)width) * w);
enc.BitmapTransform.ScaledWidth = (uint)w;
await enc.FlushAsync();
img.SetSource(ras);
}
}
}
return img;
}