public static async Task SaveStreamToFile(Windows.Storage.Streams.IRandomAccessStream stream, Windows.Storage.IStorageFile file) { using var fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite); var buffer = new byte[stream.Size]; var ibuffer = buffer.AsBuffer(); stream.Seek(0); await stream.ReadAsync(ibuffer, (uint)stream.Size, Windows.Storage.Streams.InputStreamOptions.None); await fileStream.WriteAsync(ibuffer); }