Swift 安全区域布局指南和视觉格式语言

Swift 安全区域布局指南和视觉格式语言

swift
import UIKit
class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let titleLabel = UILabel()
        titleLabel.text = "Welcome to my app"
        titleLabel.textAlignment = .center
        
        let subtitleLabel = UILabel()
        subtitleLabel.text = "Enjoy your stay"
        subtitleLabel.textAlignment = .center
        
        let stackView = UIStackView(arrangedSubviews: [titleLabel, subtitleLabel])
        stackView.axis = .vertical
        stackView.spacing = 10
        stackView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(stackView)
        
        NSLayoutConstraint.activate([
            stackView.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor),
            stackView.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor),
            stackView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 20),
            stackView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -20)
        ])
    }
}