部分角圆角
UIView *view2 =[[UIView alloc]initWithFrame:CGRectMake(120,10,80,80)];
view2.backgroundColor =[UIColor redColor];
[self.view addSubview:view2];
UIBezierPath *maskPath =[UIBezierPath bezierPathWithRoundedRect:view2.bounds byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight cornerRadii:CGSizeMake(10,10)];
CAShapeLayer *maskLayer =[[CAShapeLayer alloc]init];
maskLayer.frame = view2.bounds;
maskLayer.path = maskPath.CGPath;
view2.layer.mask = maskLayer;
view2.backgroundColor =[UIColor colorWithWhite:0.509 alpha:0.6]uiview设置透明色
