iOS控件圆角与半圆角

开发过程中难免用到圆角以及恶心的半圆角，看代码

半圆角：这是把左边的两个角切成了圆角

                UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:btn.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomLeft) cornerRadii:CGSizeMake(itemHeight/2,itemHeight/2)];//圆角大小
                CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
                maskLayer.frame = btn.bounds;
                maskLayer.path = maskPath.CGPath;
                btn.layer.mask = maskLayer;

圆角比较容易

　　　　 _label.clipsToBounds = YES;
            _label.layer.cornerRadius =3;