在 Swift 2.3中， 您可以这样做

let maskPath = UIBezierPath(roundedRect: anyView.bounds,
            byRoundingCorners: [.BottomLeft, .BottomRight],
            cornerRadii: CGSize(width: 10.0, height: 10.0))

let shape = CAShapeLayer()
shape.path = maskPath.CGPath
view.layer.mask = shape

在 Objective-C中， 您可以使用UIBezierPathclass方法

bezierPathWithRoundedRect:byRoundingCorners:cornerRadii:

示例实现-

// set the corner radius to the specified corners of the passed container
- (void)setMaskTo:(UIView*)view byRoundingCorners:(UIRectCorner)corners
{
    UIBezierPath *rounded = [UIBezierPath bezierPathWithRoundedRect:view.bounds
                                                  byRoundingCorners:corners
                                                        cornerRadii:CGSizeMake(10.0, 10.0)];
    CAShapeLayer *shape = [[CAShapeLayer alloc] init];
    [shape setPath:rounded.CGPath];
    view.layer.mask = shape;
}

并将上述方法称为-

[self setMaskTo:anyView byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight];