以编程方式满足两个自动布局约束-- Swift

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let view1 = UIView()
        view1.translatesAutoresizingMaskIntoConstraints = false
        view1.backgroundColor = .red
        view.addSubview(view1)
        
        let view2 = UIView()
        view2.translatesAutoresizingMaskIntoConstraints = false
        view2.backgroundColor = .blue
        view.addSubview(view2)
        
        NSLayoutConstraint.activate([
            view1.topAnchor.constraint(equalTo: view.topAnchor, constant: 20),
            view1.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
            view1.trailingAnchor.constraint(equalTo: view2.leadingAnchor, constant: -20),
            view1.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20),
            
            view2.topAnchor.constraint(equalTo: view.topAnchor, constant: 20),
            view2.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20),
            view2.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.5),
            view2.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20)
        ])
    }
}