I'm having trouble setting constraints to a label programmatically in Swift. I want the label to fill the entire screen. But I dont know how to do.

Thank you for your help.

CodePudding user response：

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let label = UILabel()
        label.text = "Hello"
        label.backgroundColor = UIColor.yellow
            
        self.view.addSubview(label)
        label.translatesAutoresizingMaskIntoConstraints = false
        
        let width: NSLayoutConstraint
        width = label.widthAnchor.constraint(equalTo: self.view.widthAnchor, multiplier: 1)

        let top: NSLayoutConstraint
        top = label.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor)
        
        let bottom: NSLayoutConstraint
        bottom = label.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor)
            

        width.isActive = true
        bottom.isActive = true
        top.isActive = true
        
    }
}