制作自定义形状图像视图iOS Swift 4.2

您可以这样做:

func curvedShapeFor(view: UIImageView, curvedPercent:CGFloat) ->UIBezierPath
{
    let path = UIBezierPath()
    path.move(to: CGPoint(x:0, y:0))
    path.addLine(to: CGPoint(x:view.bounds.size.width, y:0))
    path.addLine(to: CGPoint(x:view.bounds.size.width, y:view.bounds.size.height - (view.bounds.size.height*curvedPercent)))
    path.addQuadCurve(to: CGPoint(x:0, y:view.bounds.size.height - (view.bounds.size.height*curvedPercent)), controlPoint: CGPoint(x:view.bounds.size.width/2, y:view.bounds.size.height))
    path.addLine(to: CGPoint(x:0, y:0))
    path.close()

    return path
}

这样应用:

let shapeLayer = CAShapeLayer(layer: imageView.layer)
shapeLayer.path = self.curvedShapeFor(view: imageView,curvedPercent: 0.6).cgPath
shapeLayer.frame = imageView.bounds
shapeLayer.masksToBounds = true
imageView.layer.mask = shapeLayer