Auto layout not set properly when give equal width constrains to buttons - ios

Question

I see many solution and applied auto layout constrains but still i am not getting desired solution.
Current Result:
Constrains given to all button:
View Hierarchy:

Answer 1

Assuming that what do you want is letting the 3 buttons equal each others and filling the width of screen using the Interface Builder (with no code, i.e: not programmatically), this is a solution:
you don't need to add them in views. just follow these steps:
let's start with this:
note that the buttons don't have any constraints -yet-, just add them to the to the bottom of the view (or where ever you want to display them, for this solution, I will display them in bottom of the screen). Make sure that the 3 of them have the same size.
Adding constraints to the orange button:
add the following constraints:
leading, bottom space, and equal height.
Adding constraints to the blue button:
add the following constraints:
trailing, bottom space and equal height.
Adding constraints to the cyan button:
ctrl + drag from the cyan button to the orange button and add the following constraints: horizontal spacing and center vertically.
ctrl + drag from the cyan button to the blue button and add the following constraints: horizontal spacing.
bottom space and equal height.
So far so good, we are almost done!
Now, select the 3 buttons and add the following constraint: equal widths.
Your buttons should look like this:
Now, all you have to do is select each of the two horizontal spacing constraints and set their constants to 0 -from the size inspector-:
AND there you go:
I hope this helped, Cheers Up.

Answer 2

Sorry for solution in code.. .Swift 3.0:
let button1 = UIButton()
let button2 = UIButton()
let button3 = UIButton()
let buttons = [button1, button2, button3]
button1.backgroundColor = .red
button2.backgroundColor = .blue
button3.backgroundColor = .green
buttons.forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
view.addSubview($0)
}
buttons.forEach {
let cnt1 = NSLayoutConstraint(item: $0, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1, constant: 0)
let cnt2 = NSLayoutConstraint(item: $0, attribute: .height, relatedBy: .equal, toItem: view, attribute: .height, multiplier: 0.2, constant: 0)
view.addConstraints([cnt1, cnt2])
}
let cnt1 = NSLayoutConstraint(item: button1, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1, constant: 0)
let cnt2 = NSLayoutConstraint(item: view, attribute: .trailing, relatedBy: .equal, toItem: button3, attribute: .trailing, multiplier: 1, constant: 0)
let cnt3 = NSLayoutConstraint(item: button2, attribute: .width, relatedBy: .equal, toItem: button1, attribute: .width, multiplier: 1, constant: 0)
let cnt4 = NSLayoutConstraint(item: button3, attribute: .width, relatedBy: .equal, toItem: button2, attribute: .width, multiplier: 1, constant: 0)
let cnt5 = NSLayoutConstraint(item: button2, attribute: .leading, relatedBy: .equal, toItem: button1, attribute: .trailing, multiplier: 1, constant: 0)
let cnt6 = NSLayoutConstraint(item: button3, attribute: .leading, relatedBy: .equal, toItem: button2, attribute: .trailing, multiplier: 1, constant: 0)
view.addConstraints([cnt1, cnt2, cnt3, cnt4, cnt5, cnt6])

Answer 3

Are you trying to lay out three buttons horizontally that have equal height and width? I think you can achieve this without using UIViews. I set constraints like as follows.
This is a simulator screenshot.