How to center on the x-axis?

Question

iOS

dateNow.frame = CGRect(x: screen.width/2 , y: 50, width: screen.width/3 , height: screen.height/4)

Why is it not in the center? And how to center on the x-axis ???

Answer 1

The left side of the square is clearly centered on the screen, so that the current code runs correctly. In order for the square itself to be centered along the X axis, you need to additionally move it to the left by half its width. That is, the code should be like this:

dateNow.frame = CGRect(x: screen.width/2 - screen.width/3/2 , y: 50, width: screen.width/3 , height: screen.height/4)

Answer 2

Apple recommends using Autolayout, not frames, and there are bindings to the central axes: NSLayoutAttributeCenterX, NSLayoutAttributeCenterY, you can add offsets for them. Moreover, you can do this both in IB (storyboard or xib), and in code using VFL (Visual Format Language).

Answer 3

you can also set constraint