#autolayout programmatically animation

버튼을 누를때마다 UIView가 조금씩 올라가게 하기

viewDidLoad보다 먼저 실행되는 loadView()에 작성하기로 함.

전체 코드

import UIKit

class ViewController: UIViewController {
    
    var myViewBottomConstraint : NSLayoutConstraint?
    //bottom앵커가 변하게 되므로 var로 선언.
    
    override func loadView() {
        super.loadView()
        
        self.view.backgroundColor = .systemOrange //view의 배경색
        
        let upButton = UIButton(type: .system) //눌렀을 때 느낌
        let myView = UIView()
        
        self.view.addSubview(upButton)
        
        upButton.translatesAutoresizingMaskIntoConstraints = false
        upButton.setTitle("위로 올리기", for: .normal)
        upButton.setTitleColor(.black, for: .normal)
        upButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 30)
        upButton.backgroundColor = .white
        upButton.layer.cornerRadius = 8
        
        upButton.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
        
        upButton.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 200).isActive = true
        upButton.addTarget(self, action: #selector(moveViewUp), for: .touchUpInside) //액션을 넣어줌.
        upButton.contentEdgeInsets = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
        
        self.view.addSubview(myView)
        
        myView.translatesAutoresizingMaskIntoConstraints = false
        myView.backgroundColor = .blue
        myView.layer.cornerRadius = 8
        NSLayoutConstraint.activate([
            myView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
            myView.widthAnchor.constraint(equalToConstant: 100),
            myView.heightAnchor.constraint(equalToConstant: 50),
            //myView.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor)
        ])
        
        myViewBottomConstraint = NSLayoutConstraint(item: myView, attribute: .bottom, relatedBy: .equal, toItem: self.view.safeAreaLayoutGuide, attribute: .bottom, multiplier: 1.0, constant: 0)
        // constant를 변경시켜주기위해 이렇게 설정.
        
        myViewBottomConstraint?.isActive = true
        
    }
    
    @objc fileprivate func moveViewUp(){
        print("ViewController - viewDidLoad()")
        UIViewPropertyAnimator(duration: 1, curve: .easeIn, animations: {
            self.view.layoutIfNeeded()
        }).startAnimation()
        myViewBottomConstraint?.constant -= 100
    }
// 버튼을 누를때마다 위로 올라가도록 100씩 마이너스해줌.
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        
    }
}

@objc에서 애니메이션을 넣었는데 잘 안됐다. 나중에 다시 해봐야겠다.

참고

정대리님 Youtube