设置控件单个或某几个角为圆角的实现

-(void)changeButtonStyle:(UIButton*)button style:(NSInteger)style{
UIRectCorner corners;
switch (style) {
case 0:
corners = UIRectCornerBottomLeft | UIRectCornerTopLeft;
break;
case 1:
corners = UIRectCornerTopRight | UIRectCornerBottomRight;
break;
default:
corners = UIRectCornerAllCorners;
break;
}
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:button.bounds
byRoundingCorners:corners
cornerRadii:CGSizeMake(5.0, 5.0)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = button.bounds;
maskLayer.path = maskPath.CGPath;
button.layer.mask = maskLayer;
}

不仅仅是button，所有的view都可以进行类似设置。

UIRectCornerTopLeft、 UIRectCornerBottomLeft、UIRectCornerTopRight、UIRectCornerBottomRight分别对应左上、左下、右上、右下，根据实际需要，进行或运算，生成所需的UIRectCorner。