圆化 UIView 的一些角并圆化视图层的边框

Question

我正在尝试将 UIView 的底部两个角变圆，并使图层的边框也变圆。我目前正在做：

UIRectCorners corners = UIRectCornerBottomLeft | UIRectCornerBottomRight;
CGSize radii = CGSizeMake(kThisViewCornerRadius, kThisViewCornerRadius);
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:myView.bounds
                                           byRoundingCorners:corners
                                                 cornerRadii:radii];

CAShapeLayer *maskLayer = [CAShapeLayer layer];
[maskLayer setPath:path.CGPath];
myView.layer.mask = maskLayer;

这适用于普通视图。但是，myView 的图层有其borderColor 和borderWidth 设置，从截图中可以看出，图层的边框没有变圆：

我还尝试子类化 UIView 并从 +[Class layerClass] 返回 [CAShapeLayer layer]，并将视图的图层设置为一个形状图层，但边框最终位于视图的子视图下方。

是否可以圆化视图的某些角，圆化视图层的边框，并将子视图裁剪到层的边框下方？

请注意，这不是关于如何圆角而不是其他角，而是关于如何使笔划正确运行。

Answer 1

感谢David Rönnqvist 的评论，我找到了一种新的思考方式。

我试图在一层中进行圆角和笔触。相反，我将其分为两层：一层用于遮罩视图层以圆角，另一层在视图中添加笔触。

UIView *containerView = [[UIView alloc] initWithFrame:someFrame];

UIRectCorners corners = UIRectCornerBottomLeft | UIRectCornerBottomRight;
CGSize radii = CGSizeMake(kThisViewCornerRadius, kThisViewCornerRadius);

UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:myView.bounds
                                           byRoundingCorners:corners
                                                 cornerRadii:radii];

// Mask the container view’s layer to round the corners.
CAShapeLayer *cornerMaskLayer = [CAShapeLayer layer];
[cornerMaskLayer setPath:path.CGPath];
containerView.layer.mask = cornerMaskLayer;

// Make a transparent, stroked layer which will dispay the stroke.
CAShapeLayer *strokeLayer = [CAShapeLayer layer];
strokeLayer.path = path.CGPath;
strokeLayer.fillColor = [UIColor clearColor].CGColor;
strokeLayer.strokeColor = [UIColor redColor].CGColor;
strokeLayer.lineWidth = 2; // the stroke splits the width evenly inside and outside,
                           // but the outside part will be clipped by the containerView’s mask.

// Transparent view that will contain the stroke layer
UIView *strokeView = [[UIView alloc] initWithFrame:containerView.bounds];
strokeView.userInteractionEnabled = NO; // in case your container view contains controls
[strokeView.layer addSublayer:strokeLayer];

// configure and add any subviews to the container view

// stroke view goes in last, above all the subviews
[containerView addSubview:strokeView];

Answer 2

Zev Eisenberg 的答案是正确的。

虽然我更喜欢：

[self.layer addSublayer:strokeLayer];

而不是创建和添加子视图：

CGSize radii = CGSizeMake(radius, radius);

UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                           byRoundingCorners:corners
                                                 cornerRadii:radii];

// Mask the container view’s layer to round the corners.
CAShapeLayer *cornerMaskLayer = [CAShapeLayer layer];
[cornerMaskLayer setPath:path.CGPath];
self.layer.mask = cornerMaskLayer;

// Make a transparent, stroked layer which will dispay the stroke.
CAShapeLayer *strokeLayer = [CAShapeLayer layer];
strokeLayer.path = path.CGPath;
strokeLayer.fillColor = [UIColor clearColor].CGColor;
strokeLayer.strokeColor = color.CGColor;
strokeLayer.lineWidth = 2; // the stroke splits the width evenly inside and outside,
// but the outside part will be clipped by the containerView’s mask.

[self.layer addSublayer:strokeLayer];

Answer 3

这是小代码。 Alloc 初始化一个视图并发送到此方法以获取圆角。您可以选择绕过您想要的任何角落。还要给阴影描边颜色。

 -(void) setMaskTo:(UIView*)view byRoundingCorners:(UIRectCorner)corners withColor:  (UIColor*) color
{
 UIBezierPath* rounded = [UIBezierPath bezierPathWithRoundedRect:view.bounds  byRoundingCorners:corners cornerRadii:CGSizeMake(9.0, 9.0)];

CAShapeLayer* shape = [[[CAShapeLayer alloc] init] autorelease];
[shape setPath:rounded.CGPath];
shape.strokeColor = [[UIColor grayColor] CGColor];

view.backgroundColor=color;
view.layer.mask = shape;
}

像这样调用方法。

[self setMaskTo:ABCView byRoundingCorners:UIRectCornerAllCorners withColor:[UIColor greenColor]];