ios - BezierPath 和掩蔽

Question

我想将 UIBezierPath 设置为 View 中的掩码:目标是这样的:

所以我用框架绘制 View :

CGFloat round = 80;
UIView *myView = [[UIView alloc] initWithFrame:CGRectMake(self.frame.size.width/2-105, 0, 210, 60+round)];
myView.backgroundColor = [UIColor redColor];

然后尝试添加 BezierMask:

UIBezierPath *aPath = [UIBezierPath bezierPath];

CGSize viewSize = CGSizeMake(myView.frame.size.width, myView.frame.size.height); //(210,80)
CGPoint startPoint = CGPointMake(myView.frame.origin.x,myView.frame.origin.y); //(279,0)

[aPath moveToPoint:startPoint]; //(279,0)

[aPath addLineToPoint:CGPointMake(startPoint.x+viewSize.width,startPoint.y)]; //(489,0)
[aPath addLineToPoint:CGPointMake(startPoint.x+viewSize.width,startPoint.y+viewSize.height-round)]; //(489,60)
[aPath addQuadCurveToPoint:CGPointMake(startPoint.x,startPoint.y+viewSize.height-round) controlPoint:CGPointMake(startPoint.x+(viewSize.width/2),80)]; //(279,60) : (384,80)

[aPath closePath];

CAShapeLayer *layer = [CAShapeLayer layer];
layer.frame = myView.bounds;
layer.path = aPath.CGPath;
myView.layer.mask = layer;

[self addSubview:myView];

但在那之后我的观点就消失了。为什么？

Answer 1

我猜你对 mask 层使用了不正确的协调。您的 mask 层必须位于它 mask 的 View 中，而不是在 View 的父 View 中。

尝试这些改变:

CGSize viewSize = myView.bounds.size;
CGPoint startPoint = CGPointZero;

经过这些小修改后的代码对我来说没问题。