Autolayout aspect ratio for UIImageView / UIView

Question

How to set autolayout for UIImageView /UIView so that the image view width and height increases a bit for iphone 6 and 6 plus. I have tried adding the constraint Aspect rati

Answer 1

Sometimes playing with aspect ratio constraint doesn't help. In such a condition use equal width and equal height constraint with a formula I will explain as below with an example.

Say i have a UIView taking whole of the width of iPhone 5 i.e. 320 points. (remember 1 point = 2 pixel for retina display) and a height of 46 points. I want a button (Width = 30 point, height = 60 points) inside this UIView which would resize as per different phones with the same aspect ratio. I will do Control drag from the button to the UIView and select equal width first time and then will do the same thing again with Equal heights. Following this I will select the constraint and will make sure that the first item is the button and second item is the UIView. I will use this formula to calculate the multiplier then:

To calculate width multiplier: 60 (width of the button) / 320 (width of the UIView) * 100 = 18.75%

To calculate height multiplier: 30 (height of the button) / 46 (height of the UIView) * 100 = 65.217%

Now enter this multiplier (remember to use %age sign as well just like above) and this should resize the button for different sizes of iPhone screen.