UIBezierPath *maskPath =[UIBezierPathbezierPathWithRoundedRect:button.boundsbyRoundingCorners:UIRectCornerTopLeft|UIRectCornerTopRightcornerRadii:CGSizeMake(4.0,4.0)];
CAShapeLayer *maskLayer =[ [CAShapeLayer alloc]init];
maskLayer.frame = button.bounds;
maskLayer.path = maskPath.CGPath;
button.layer.mask = maskLayer;
以上是将button的左上和右上的边角设置为半径4.0的圆角
UIRectCorneryou4种属性:
UIRectCornerTopLeft;左上
UIRectCornerTopRight;右上
UIRectCornerBottomLeft;左下
UIRectCornerBottomRight;右下
UIRectCornerAllCorners;4个边角
