更新时间:2023-01-05 13:32:04
这是一个棘手的问题. UIView
的clipsToBounds
是获得圆角所必需的.但是CALayer
的masksToBounds
必须为false
,因此阴影是可见的.不知何故,如果不覆盖drawRect
,一切都会正常,但实际上不应该.
This is a tricky one. UIView
's clipsToBounds
is necessary to get the rounded corners. But CALayer
's masksToBounds
has to be false
so the shadow is visible. Somehow, everything works if drawRect
is not overridden, but actually it shouldn't.
解决方案是创建一个超级视图以提供阴影(在下面的演示中,这是shadowView
).您可以在Playground中测试以下内容:
The solution is to create a superview to provide the shadow (in the demonstration below this is the shadowView
). You can test the following in Playground:
class MyView : UIView {
override func drawRect(rect: CGRect) {
let c = UIGraphicsGetCurrentContext()
CGContextAddRect(c, CGRectMake(10, 10, 80, 80))
CGContextSetStrokeColorWithColor(c , UIColor.redColor().CGColor)
CGContextStrokePath(c)
}
}
let superview = UIView(frame: CGRectMake(0, 0, 200, 200))
let shadowView = UIView(frame: CGRectMake(50, 50, 100, 100))
shadowView.layer.shadowColor = UIColor.blackColor().CGColor
shadowView.layer.shadowOffset = CGSizeZero
shadowView.layer.shadowOpacity = 0.5
shadowView.layer.shadowRadius = 5
let view = MyView(frame: shadowView.bounds)
view.backgroundColor = UIColor.whiteColor()
view.layer.cornerRadius = 10.0
view.layer.borderColor = UIColor.grayColor().CGColor
view.layer.borderWidth = 0.5
view.clipsToBounds = true
shadowView.addSubview(view)
superview.addSubview(shadowView)
结果: