在 Windows 10 UAP 中将 BitmapImage 或 IRandomAccessStream 转换为字节数组

Question

谁能帮帮我。我不明白如何将 BitmapImage 或 IRandomAccessStream 转换为字节数组。 我试试：

foreach (StorageFile file in files)
{
    BitmapImage src = new BitmapImage();

    using (IRandomAccessStream stream = await file.OpenReadAsync())
    {
        await src.SetSourceAsync(stream);

        WriteableBitmap bitMap = new WriteableBitmap(src.PixelWidth, src.PixelHeight);
        await bitMap.SetSourceAsync(stream);
    }
}

然后我有 WriteableBitmap 并试试这个：

private byte[] ImageToByeArray(WriteableBitmap wbm)
{
    using (Stream stream = wbm.PixelBuffer.AsStream())
    using (MemoryStream memoryStream = new MemoryStream())
    {
        stream.CopyTo(memoryStream);
        return memoryStream.ToArray();
    }
}

但这对我不起作用;(

Answer 1

应该这样做：

    async Task<byte[]> Convert(IRandomAccessStream s)
    {
        var dr = new DataReader(s.GetInputStreamAt(0));
        var bytes = new byte[s.Size];
        await dr.LoadAsync((uint)s.Size);
        dr.ReadBytes(bytes);
        return bytes;
    }

Answer 2

我在我的 WPF 应用程序中使用此解决方案将数据库中的图像保存为 byte[]。它也应该适用于您的情况。

public static byte[] ImageToString(System.Windows.Media.Imaging.BitmapImage img) {
    System.IO.MemoryStream stream = new System.IO.MemoryStream();
    System.Windows.Media.Imaging.BmpBitmapEncoder encoder = new System.Windows.Media.Imaging.BmpBitmapEncoder();
    encoder.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create((System.Windows.Media.Imaging.BitmapSource)img));
    encoder.Save(stream);
    stream.Flush();

    return stream.ToArray();
}