聊天汽泡实现的两种的方式：1、用CAShapeLayer和UIBezierPath创建一个不规则layer,然后把你要设置汽泡的View的layer的mask设置创建的不规则layery就行了。 上代码：
-(CAShapeLayer*)maskLayer:(UIView* )view{
CGFloat viewWidth = CGRectGetWidth(view.frame);
CGFloat viewHeight = CGRectGetHeight(view.frame);
CGFloat rightSpace = 8.;
CGFloat topSpace = 8.;
CGPoint point1 = CGPointMake(0, 0);
CGPoint point2 = CGPointMake(viewWidth-rightSpace, 0);
CGPoint point3 = CGPointMake(viewWidth-rightSpace, topSpace);
CGPoint point4 = CGPointMake(viewWidth, topSpace+2);
CGPoint point5 = CGPointMake(viewWidth-rightSpace, topSpace+10.);
CGPoint point6 = CGPointMake(viewWidth-rightSpace, viewHeight);
CGPoint point7 = CGPointMake(0, viewHeight);
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:point1];
[path addLineToPoint:point2];
[path addLineToPoint:point3];
[path addLineToPoint:point4];
[path addLineToPoint:point5];
[path addLineToPoint:point6];
[path addLineToPoint:point7];
[path closePath];
CAShapeLayer *layer = [CAShapeLayer layer];
layer.path = path.CGPath;
return layer;
}
比如想做微信发图片那种功能
UIImageView *bubbleBackgroundView = [[bubbleBackgroundView alloc]init];
bubbleBackgroundView.frame = CGRectMake(0, 0, 200,100);
bubbleBackgroundView.layer.mask=[self maskLayer: bubbleBackgroundView];
效果图
粘贴图片.png
第二种方式刚很简单，需要UI切一个汽泡的图（其实总的来说是两种实现方式是一样，只不过是获取不规则的layer的方式不同而已）。
UIImageView *maskImageView = [[UIImageView alloc]initWithFrame:self.bubbleBackgroundView.bounds];
UIImage *image = [self imageNamed:@"chat_to_bg_white_boderBlock" ofBundle:@"RongCloud.bundle"];
maskImageView.image = [image
resizableImageWithCapInsets:UIEdgeInsetsMake(image.size.height * 0.8, image.size.width * 0.2,
image.size.height * 0.2, image.size.width * 0.8)];;
self.bubbleBackgroundView.layer.mask=maskImageView.layer;
效果图：1、UI切的汽泡图
chat_from_bg_normal@2x.png
2、做出来的效果图
粘贴图片2.png
注意：第一种是没有圆角哦，第二种有
