小编L03*_*03n的帖子

在iOS 12.2上。使用UIAlertController的actionSheet Xcode时，遇到此问题的人都会遇到约束错误

相同的代码在iOS 12.1上运行，没有错误

我已经在Xcode 10.2和10.1上测试了此代码

class ViewController: UIViewController {

    let Click : UIButton = {
        let button = UIButton(type: UIButton.ButtonType.system)
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setTitle("OK", for: .normal)
        button.tintColor = UIColor.blue
        button.addTarget(self, action: #selector(click(_:)), for: UIControl.Event.touchUpInside)
        return button
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(Click)
        Click.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        Click.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
    }


    @objc func click(_ sender: UIButton) {
        let optionMenu = UIAlertController(title: nil, message: "Choose Option", preferredStyle: .actionSheet)

        let deleteAction = UIAlertAction(title: "Delete", style: .default)
        let saveAction = …