CALayer *sublayer = [CALayer layer];
sublayer.backgroundColor = [UIColor purpleColor].CGColor;
sublayer.shadowOffset = CGSizeMake(, );
sublayer.shadowRadius = 5.0;
sublayer.shadowColor = [UIColor blackColor].CGColor;
sublayer.shadowOpacity = 0.8;
sublayer.frame = CGRectMake(, , , );
sublayer.borderColor = [UIColor blackColor].CGColor;
sublayer.borderWidth = 2.0;
sublayer.cornerRadius = 10.0;
[self.view.layer addSublayer:sublayer]; CALayer *imageLayer = [CALayer layer];
imageLayer.frame = sublayer.bounds;
imageLayer.cornerRadius = 10.0;
imageLayer.contents = (id)[UIImage imageNamed:@"snaguosha.png"].CGImage;
imageLayer.masksToBounds = YES;
[sublayer addSublayer:imageLayer]; CALayer *customDrawn = [CALayer layer];
customDrawn.delegate = self;
customDrawn.backgroundColor = [UIColor greenColor].CGColor;
customDrawn.frame = CGRectMake(, , , );
customDrawn.shadowOffset = CGSizeMake(, );
customDrawn.shadowRadius = 5.0;
customDrawn.shadowColor = [UIColor blackColor].CGColor;
customDrawn.shadowOpacity = ;
customDrawn.cornerRadius = 10.0;
customDrawn.borderColor = [UIColor blackColor].CGColor;
customDrawn.borderWidth = 2.0;
customDrawn.masksToBounds = YES;
[self.view.layer addSublayer:customDrawn];
[customDrawn setNeedsDisplay];

以上代码预览如下:

iOS——CALayer的shadow无效问题-LMLPHP

可以看到下方的部分没有阴影,Why?看了半天也没看出什么不一样,后来发现是因为customDrawn.masksToBounds = YES;这句代码导然不存在,如果去掉这行代码会是这样的:

iOS——CALayer的shadow无效问题-LMLPHP

阴影出来了,但是圆角没了。解决办法很简单,像上面图片的方式,里面套一层,masksToBounds作用在里层,外层显示阴影

04-25 21:51