// Caller must .Ref()
public RefCountedImage LoadAsync(string path)
{
if (!imagesByPath.ContainsKey(path))
{
Console.WriteLine($"+{path}");
var rcImage = new RefCountedImage {
Path = path
};
rcImage.Task = Task.Run(() =>
{
try
{
return(ResizeToUsefulSize(Image.FromFile(path, true)));
}
finally
{
// Loading the image (running this code) takes one reference, being in the cache takes another one,
// being used or awaited from the GUI takes a third one.
// Making running this code take one reference avoids NPE if the image is evicted before finishing
// loading.
Console.WriteLine($"@{path}");
rcImage.Unref();
}
});
imagesByPath.Add(path, rcImage.Ref());
}
return(imagesByPath.TryUse(path));
}
private void ImagesByPath_ElementEvictedEvent(string key, RefCountedImage value)
{
Console.WriteLine($"-{key}");
value.Unref();
}
