UIImageView aspect fit and center

Question

I have an image view, declared programmatically, and I am setting its image, also programmatically.

However, I find myself unable to set the image to both fit the as

Answer 1

let bannerImageView = UIImageView();
bannerImageView.contentMode = .ScaleAspectFit;
bannerImageView.frame = CGRectMake(cftX, cftY, ViewWidth, scrollHeight);