我有这样的初始化看法:
var view: UIView! = {
var perm = UIView()
perm.backgroundColor = UIColor.black
// enable auto layout
perm.translatesAutoresizingMaskIntoConstraints = false
return perm
}()
之后,我将标签添加为view
的子视图。标签初始化如下:
var title: UILabel! = {
let perm = UILabel()
perm.textColor = UIColor.white
perm.numberOfLines = 0
perm.font = UIFont.boldSystemFont(ofSize: 20)
// enable auto layout
perm.translatesAutoresizingMaskIntoConstraints = false
return perm
}()
之后,我以编程方式添加了一些约束。当我运行该应用程序时,title
显示在正确的位置,但是view
的背景色尚未设置。
编辑
这是我设置约束的方式:
view.addSubview(title)
view.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
view.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
view.bottomAnchor.constraint(equalTo: image.bottomAnchor).isActive = true
title.leadingAnchor.constraint(equalTo: title.superview!.leadingAnchor, constant: 20).isActive = true
title.trailingAnchor.constraint(equalTo: title.superview!.trailingAnchor, constant: -20).isActive = true
title.bottomAnchor.constraint(equalTo: title.superview!.bottomAnchor, constant: -20).isActive = true
答案 0 :(得分:1)
s
需要高度
view
或为标签高度加上顶部和底部填充40
view.heightAnchor.constraint(equalToConstant:200).isActive = true