how to constraint something to the center top anchor

Question

In my code below I am trying to constraint something to the top of the center point of the uiscreen. I have added a image of what I am looking for below. The code below is what I tried it pins it the center of the screen and has the object in the middle of the screen.

import UIKit

class ViewController: UIViewController {
    var box = UIImageView()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        box.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(box)
        box.backgroundColor = .systemPink
        NSLayoutConstraint.activate([

            box.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier : 0.25),
            box.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier : 0.25),
            box.centerXAnchor.constraint(equalTo: view.centerXAnchor ),
            box.centerYAnchor.constraint(equalTo: view.centerYAnchor),


        ])
    }


}

Answer 1

You need to remove centerYAnchor constraint no your box and set bottomAnchor instead.

Remove: box.centerYAnchor.constraint(equalTo: view.centerYAnchor)

Add: box.bottomAnchor.constraint(equalTo: view.centerYAnchor)

Correct constraints:

NSLayoutConstraint.activate([
    box.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.25),
    box.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.25),
    box.centerXAnchor.constraint(equalTo: view.centerXAnchor),
    box.bottomAnchor.constraint(equalTo: view.centerYAnchor)
])