ios - Set contentMode of UIImageView

Question

In Obj-C

imageView.contentMode = UIViewContentModeScaleAspectFill;

would set the contentMode.

Why does

imageView.contentMode = UIViewContentModeScaleAspectFill

not work in Swift?

Answer 1

Somewhat confusingly, Swift drops the prefix for ObjC enum values:

imageView.contentMode = .scaleAspectFill

This is because Swift already knows what enum type is being used. Alternatively, you can specify the enum too:

imageView.contentMode = UIViewContentMode.scaleAspectFill

Note: In versions of Swift before version 3, "scaleAspectFill" will need to be capitalized.