iOS >> UIButton ImageView Property >> How to set Content Mode?

Question

Is there a way to set a UIButton Image, BackgroundImage or ImageView Properties Content Mode Property?

I\'ve tried the direct approach (it didn\'t work, of course...

Answer 1

Using iOS7/8 with auto-layout, button.imageView doesn't get scaled when button is laid out, e.g. for iPhone 6:

(lldb) po button
>

(lldb) po button.imageView

After setting button's image, button.imageView assumed the size of the image, e.g. for a 320x240 image:

(lldb) po button.imageView
>

It looks like button.imageView does not respect its content mode, but actually, it is the size of the button.imageView that is the problem.

The answer is to set button's content alignment as well.

The following sets button's image, sets button.imageView's content mode, and makes button.imageView fit the size of button:

[button setImage:image forState:UIControlStateNormal];
button.imageView.contentMode = UIViewContentModeScaleAspectFill;
button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentFill;
button.contentVerticalAlignment = UIControlContentVerticalAlignmentFill;

Now, button.imageView is the same size as button, and has the desired content mode.

(lldb) po button.imageView
>

The desired result is thereby achieved. Very handy!