/// <summary>
/// Binds the image URL to the specified image view.
/// Now, every time the URL changes, the corrosponding image will be downloaded
/// and applied, but ONLY if the binding has not been disposed since the
/// download was initialized. Trust me when I say, this will fix (or avoid, I
/// suppose) a lot of headaches you didn't know you were going to get.
/// </summary>
/// <typeparam name="TModel">The type of the model.</typeparam>
/// <param name="img">The img.</param>
/// <param name="model">The model.</param>
/// <param name="getVal">The get value.</param>
/// <returns></returns>
public static IBinding BindImageUrl <TModel>(this UIImageView img, TModel model, Expression <Func <TModel, int> > getVal)
where TModel : INotifyPropertyChanged
{
var disposed = false;
BlobCache.EnsureInitialized();
var binding = (Binding)img.Bind(
model,
getVal,
async(i, bookId) =>
{
var url = ApiConfig.GetCoverUrl(bookId, (int)img.Frame.Width, (int)img.Frame.Height);
UIImage uiImage;
try
{
var image = await BlobCache.UserAccount.LoadImageFromUrl(
url,
url,
false,
null,
null,
DateTimeOffset.Now.AddDays(7));
uiImage = image.ToNative();
}
catch (WebException)
{
uiImage = UIImage.FromBundle("Icons/UnknownImage.png");
}
if (disposed)
{
return;
}
img.Image = uiImage;
});
binding.With(() => disposed = true);
return(binding);
}