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;
以上是將button的左上和右上的邊角設置為半徑4.0的圓角
UIRectCorneryou4種屬性:
UIRectCornerTopLeft;左上
UIRectCornerTopRight;右上
UIRectCornerBottomLeft;左下
UIRectCornerBottomRight;右下
UIRectCornerAllCorners;4個邊角