我如何用阴影掩盖CALayer,以便阴影只在路径之外？我不希望透明视图背后的阴影.
- shadowLayer.shadowOffset = CGSizeMake(x,y);
- shadowLayer.shadowRadius = radius;
- shadowLayer.shadowOpacity = opacity;
- shadowLayer.shadowColor = color.CGColor;
- shadowLayer.shadowPath = [UIBezierPath bezierPathWithRect:view.bounds].CGPath;
谢谢.
解决方法
我会回答我自己的问题.为视图添加新的阴影层.如果设置正确,这应适用于任何shadowPath.
- float radius = 8;
- float opacity = 0.5f;
- float x = 4;
- float y = 6;
- UIColor *color = [UIColor blackColor];
- // Shadow layer
- CALayer *shadowLayer = [CALayer layer];
- shadowLayer.shadowOffset = CGSizeMake(x,y);
- shadowLayer.shadowRadius = radius;
- shadowLayer.shadowOpacity = opacity;
- shadowLayer.shadowColor = color.CGColor;
- shadowLayer.shadowPath = [UIBezierPath bezierPathWithRect:view.frame].CGPath; // Or any other path
- // Shadow mask frame
- CGRect frame = CGRectInset(view.layer.frame,-2*radius,-2*radius);
- frame = CGRectOffset(frame,x,y);
- // Translate shadowLayer shadow path to mask layer's coordinate system
- CGAffineTransform trans = CGAffineTransformMakeTranslation(-view.frame.origin.x-x+2*radius,-view.frame.origin.y-y+2*radius);
- // Mask path
- CGMutablePathRef path = CGPathCreateMutable();
- CGPathAddRect(path,nil,(CGRect){.origin={0,0},.size=frame.size});
- CGPathAddPath(path,&trans,shadowLayer.shadowPath);
- CGPathCloseSubpath(path);
- // Mask layer
- CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
- maskLayer.frame = frame;
- maskLayer.fillRule = kCAFillRuleEvenOdd;
- maskLayer.path = path;
- shadowLayer.mask = maskLayer;
- [view.layer.superlayer insertSublayer:shadowLayer below:view.layer];
