我认为这里的子类化UIView
和重写drawRect
重写.为什么不在UIView
上添加一个扩展,并添加边框子视图?
@discardableResult
func addBorders(edges: UIRectEdge,
color: UIColor,
inset: CGFloat = 0.0,
thickness: CGFloat = 1.0) -> [UIView] {
var borders = [UIView]()
@discardableResult
func addBorder(formats: String...) -> UIView {
let border = UIView(frame: .zero)
border.backgroundColor = color
border.translatesAutoresizingMaskIntoConstraints = false
addSubview(border)
addConstraints(formats.flatMap {
NSLayoutConstraint.constraints(withVisualFormat: $0,
options: [],
metrics: ["inset": inset, "thickness": thickness],
views: ["border": border]) })
borders.append(border)
return border
}
if edges.contains(.top) || edges.contains(.all) {
addBorder(formats: "V:|-0-[border(==thickness)]", "H:|-inset-[border]-inset-|")
}
if edges.contains(.bottom) || edges.contains(.all) {
addBorder(formats: "V:[border(==thickness)]-0-|", "H:|-inset-[border]-inset-|")
}
if edges.contains(.left) || edges.contains(.all) {
addBorder(formats: "V:|-inset-[border]-inset-|", "H:|-0-[border(==thickness)]")
}
if edges.contains(.right) || edges.contains(.all) {
addBorder(formats: "V:|-inset-[border]-inset-|", "H:[border(==thickness)]-0-|")
}
return borders
}
// Usage:
view.addBorder(edges: [.all]) // All with default arguments
view.addBorder(edges: [.top], color: .green) // Just Top, green, default thickness
view.addBorder(edges: [.left, .right, .bottom], color: .red, thickness: 3) // All except Top, red, thickness 3
有了这段代码,您也不再依赖于您的子类,您可以将它应用于从UIView
继承的任何东西--在您的项目中可重用,以及其他任何东西.将其他参数传递给您的方法以定义其他 colored颜色 和宽度.有很多 Select .