intrinsicContentSize를 갖는 경우

1. UILabel

2. UIButton

3. UITextField

4. UIImageView

5. UITextView

안 갖는데 헷갈리는 것들

1. UIStackView

2. UIVivew

갖는 것 중 주의해야 할 것

UIImageView

-> Image가 없다면 intrinsicContentSize를 갖지 않는다.

-> ImageView의 크기가 아닌 image의 크기를 반환한다.

아래는 테스트 코드

import SnapKit
import Kingfisher
import UIKit

class ViewController: UIViewController {
    let button: UIButton = {
        let button = UIButton()
        button.setTitle("이미지 교체", for: .normal)
        return button
    }()
    let button2: UIButton = {
        let button = UIButton()
        button.setTitle("디버그 출력", for: .normal)
        return button
    }()
    lazy var textLabel = UILabel()
    let stackView = UIStackView()
    let scrollView = UIScrollView()
    let imageView: UIImageView = {
        let view = UIImageView()
        return view
    }()



    override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(imageView)
        imageView.snp.makeConstraints {
            $0.centerX.centerY.equalToSuperview()
            $0.height.width.equalTo(300)
        }
        imageView.contentMode = .scaleAspectFit
        imageView.backgroundColor = .cyan

        imageView.kf.setImage(with: URL(string: "https://random.imagecdn.app/300/600"))

        view.addSubview(button)
        button.snp.makeConstraints {
            $0.leading.equalToSuperview()
            $0.bottom.equalTo(view.safeAreaLayoutGuide)
        }
        view.addSubview(button2)
        button2.snp.makeConstraints {
            $0.trailing.equalToSuperview()
            $0.bottom.equalTo(view.safeAreaLayoutGuide)
        }

        button.addAction(UIAction { [weak self] _ in
            let width = Int.random(in: 100...500)
            let height = Int.random(in: 100...500)
            let url = URL(string: "https://random.imagecdn.app/\(width)/\(height)")
            self?.imageView.kf.setImage(with: url)
        }, for: .touchUpInside)

        button2.addAction(UIAction { [weak self] _ in
            guard let self else { return }
            print(self.imageView.intrinsicContentSize)
        }, for: .touchUpInside)
    }
}

UITextField

-> 스크롤이 가능해지는 순간 intrinsicContentSize를 갖지 않는다.