UIView 的clipsToBound导致气泡阴影显示不正常

最近实现一个气泡的效果，使用CGPathRef自定义不规则的气泡样式，但是由于使用了UIView的clipsToBounds属性导致气泡显示不一样，如果设置了clipsToBounds 会导致设置的shadow不能正常显示，带入如下：

UIView *contentView = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 140, 45)]; [self.view addSubview:contentView]; contentView.clipsToBounds = YES; ShadowView *shadowView = [[ShadowView alloc] initWithFrame:contentView.bounds]; [contentView addSubview:shadowView];

设置clipsToBounds=YES 显示效果如下： 这是由于设置contentView的clipsToBound=YES, 那contentView上的subview在绘制shadow的时候，由于shadow已经超出frame，所以shadow 绘制出来不是预期的效果，superview的clipsToBound 会影响subview的阴影绘制，个人觉得是一个比较大的坑。 设置clipsToBounds=NO 显示正常：

其中ShadowView 的设置气泡样式的代码如下:

- (instancetype)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { _bubbleHeight = 5; CGPathRef bubblePath = [self bubblePath]; self.opaque = FALSE; self.backgroundColor = [UIColor clearColor]; self.layer.shadowPath = bubblePath; self.layer.shadowColor = [UIColor greenColor].CGColor; self.layer.shadowRadius = 5; self.layer.shadowOpacity = 1.0; self.layer.shadowOffset = CGSizeMake(0, 0); CGPathRelease(bubblePath); } return self; } - (CGPathRef)bubblePath { CGFloat radius = CGRectGetHeight(self.bounds) / 2.0 - 5; CGFloat bubbleHeight = _bubbleHeight; CGFloat bubbleWidth = 8; CGFloat drawWidth = CGRectGetWidth(self.bounds); CGFloat drawHeight = CGRectGetHeight(self.bounds) - bubbleHeight; //left corner CGMutablePathRef bubblePath = CGPathCreateMutable(); CGPathMoveToPoint(bubblePath, NULL, radius, 0); CGPathAddArcToPoint(bubblePath, NULL, 0, 0, 0, radius, radius); //left-bottom corner CGPathAddLineToPoint(bubblePath, NULL, 0, drawHeight - radius); CGPathAddArcToPoint(bubblePath, NULL, 0, drawHeight, radius, drawHeight, radius); //bottom down-arrow CGPathAddLineToPoint(bubblePath, NULL, (drawWidth - bubbleWidth) / 2, drawHeight); CGPathAddLineToPoint(bubblePath, NULL, drawWidth / 2, drawHeight + bubbleHeight); CGPathAddLineToPoint(bubblePath, NULL, (drawWidth + bubbleWidth) / 2, drawHeight); //right-bottom corner CGPathAddLineToPoint(bubblePath, NULL, drawWidth - radius, drawHeight); CGPathAddArcToPoint(bubblePath, NULL, drawWidth, drawHeight, drawWidth, drawHeight - radius, radius); //right-top corner CGPathAddLineToPoint(bubblePath, NULL, drawWidth, radius); CGPathAddArcToPoint(bubblePath, NULL, drawWidth, 0, drawWidth - radius, 0, radius); //move brush to start point CGPathAddLineToPoint(bubblePath, NULL, radius, 0); return bubblePath; }