Question

How is the size detected from an image and then use that size to create a UIImageView, perfectly fitting the image inside?

Answer 1

Just create the UIImageView like this:

UIImageView *aImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"yourImage.png"]];

So the ImageView has the size of the image. From the Documentation of UIImageView:

This method adjusts the frame of the receiver to match the size of the specified image. It also disables user interactions for the image view by default.

I hope my answer helps you. 😀

Sandro