围绕UIView的一些角落并围绕视图的图层边界

Question

我试图围绕UIView的底部两个角落，并且图层的边框也显示为圆形。我现在正在做：

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的图层设置了borderColor和borderWidth，正如您从屏幕截图中看到的那样，图层的边框不会被舍入：

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

是否可以围绕视图的某个角落，围绕视图的图层边框，并将图层剪切到图层边框下方？

请注意，不关于如何围绕某些角落而不是其他角落，而是如何使笔划正确行为。

Answer 1

由于David Rönnqvist的评论，我想出了一种新的思考方式。

我试图在一个层中完成角落和笔划。相反，我将其分为两层：一层用于遮盖视图的图层以使角落圆角，另一层用于添加笔划。

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初始化视图并发送到此方法以获得四舍五入。你可以选择围绕你想要的任何角落。同时给出阴影笔触颜色。

 -(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]];