Ios 以编程方式设置约束
我正在尝试添加带有标签的UIView,并希望设置约束以水平和垂直地将标签放置在中心。但是代码没有按照我的要求放置它。下面是代码。标签显示在屏幕的左上角,而不是屏幕的中心Ios 以编程方式设置约束,ios,swift,label,constraints,Ios,Swift,Label,Constraints,我正在尝试添加带有标签的UIView,并希望设置约束以水平和垂直地将标签放置在中心。但是代码没有按照我的要求放置它。下面是代码。标签显示在屏幕的左上角,而不是屏幕的中心 class TestViewController: UIViewController { var title = UIView() override func viewDidLoad() { super.viewDidLoad() func presentTitle ()
class TestViewController: UIViewController {
var title = UIView()
override func viewDidLoad() {
super.viewDidLoad()
func presentTitle ()
}
func presentTitle () {
title.backgroundColor = UIColor.black
title.textColor = UIColor.white
title.font = UIFont(name: "Helvetica", size: 30)
title.textAlignment = .center
title.backgroundColor = .lightGray
title.numberOfLines = 1
title..text = vmTitleTransferredFromTaskAnalysisDetail!
self.view.addSubview(title)
title.translatesAutoresizingMaskIntoConstraints = false
title.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor).isActive = true
title.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor).isActive = true
title.eadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor).isActive = true
title.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor).isActive = true
self.view = title
}
}
删除
self.view=title
。谢谢,麦迪!它起作用了。顺便问一下,self.view=title的功能是什么?如果时间允许,请回答:)该行将视图控制器的视图替换为标题
标签,使您的标签成为整个视图控制器中的唯一视图。