iOS button边框

        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];    <span style="white-space:pre"></span>//同样来说btn也是有set方法的这里用的点语法        btn.layer.masksToBounds=YES;        btn.layer.cornerRadius=5;        btn.layer.borderWidth=2;        CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();                CGColorRef color = CGColorCreate(colorSpaceRef, (CGFloat[]){1,1,1,1});        btn.layer.borderColor=color;

效果