private async void Prueba(string url)
{
var downloadedImage = await ImageService.DownloadImage(url);
Stream stream = new MemoryStream(downloadedImage);
Myfoto.Source = ImageSource.FromStream(() => new MemoryStream(downloadedImage));
// DependencyService.Get<IFileService>().SavePicture((Preferences.Get("UserID", 0)).ToString() + ".jpg", stream);
}