How to Create layout constraints programmatically

Question

I am displaying a view in the bottom of the universal application and adding this view dynamically in my view. I want to show this view in bottom every time like iAd. in bot

Answer 1

You can use autolayout constraints programmatically like below

fileprivate func setupName(){
        let height = CGFloat(50)

        lblName.text = "Hello world"
        lblName.backgroundColor = .lightGray

        //Step 1
        lblName.translatesAutoresizingMaskIntoConstraints = false

        //Step 2
        self.view.addSubview(lblName)

        //Step 3
        NSLayoutConstraint.activate([

            lblName.leadingAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.leadingAnchor),
            lblName.trailingAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.trailingAnchor),
            lblName.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor,constant: -height),
            lblName.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor),
            ])

    }

Output screenshot