? ? // 左上和右上為圓角

? ? UIBezierPath *cornerRadiusPath = [UIBezierPath bezierPathWithRoundedRect:self.contentBGView.bounds byRoundingCorners:UIRectCornerTopRight | UIRectCornerTopLeft cornerRadii:CGSizeMake(18, 18)];

? ? CAShapeLayer*cornerRadiusLayer = [ [CAShapeLayeralloc]init];

? ? cornerRadiusLayer.frame=self.contentBGView.bounds;

? ? cornerRadiusLayer.path= cornerRadiusPath.CGPath;

? ? self.contentBGView.layer.mask= cornerRadiusLayer;