在日常开发中我们有时候会遇到View只有部分圆角的需求，这是我们可以让UI给我们切符合需求的图，那么我们能不能用代码实现这一需求呢，答案是肯定的。

上代码

给view扩展设置部分角是原角的方法
extension UIView {

    /// 设置多个圆角
    ///
    /// - Parameters:
    ///   - cornerRadii: 圆角幅度
    ///   - roundingCorners: UIRectCorner(rawValue: (UIRectCorner.topRight.rawValue) | (UIRectCorner.bottomRight.rawValue))
     public func filletedCorner(_ cornerRadii:CGSize,_ roundingCorners:UIRectCorner)  {
          let fieldPath = UIBezierPath.init(roundedRect: bounds, byRoundingCorners: roundingCorners, cornerRadii:cornerRadii )
          let fieldLayer = CAShapeLayer()
          fieldLayer.frame =bounds
          fieldLayer.path = fieldPath.cgPath
          self.layer.mask = fieldLayer
    }
}

调用

class TextViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = UIColor.white

        let frame = CGRect(x: 0, y: 0, width: 150, height: 150)
        let tempView = UIView(frame: frame)
        tempView.backgroundColor = UIColor.o
        tempView.center  = self.view.center
        view.addSubview(tempView)
        tempView.ViewCornerRadius(CGSize(width: 5, height: 5), 
        UIRectCorner(rawValue: (UIRectCorner.topLeft.rawValue)| 
        (UIRectCorner.topRight.rawValue)))
   }
}

在iOS11之前想要用代码实现部分圆角在用以上方法，但是iOS11之后就没必要这样麻烦

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = UIColor.white
        let frame = CGRect(x: 0, y: 0, width: 150, height: 150)
        let tempView = UIView(frame: frame)
        tempView.backgroundColor = UIColor.orange
        tempView.center  = view.center
        view.addSubview(tempView)

        if #available(iOS 11.0, *) {
           // iOS11:只需要带用这个系统方法就可以随意设置View的圆角了，是不是很方便，赶快试一下吧
            tempView.layer.cornerRadius = 10
            tempView.layer.maskedCorners = CACornerMask(rawValue: CACornerMask.layerMinXMinYCorner.rawValue | CACornerMask.layerMaxXMinYCorner.rawValue)
        } else {
            tempView.ViewCornerRadius(CGSize(width: 5, height: 5), UIRectCorner(rawValue: (UIRectCorner.topLeft.rawValue)|(UIRectCorner.topRight.rawValue)))
        }
    }
}

运行效果:

效果图