iOS切圆角的方式有三种
1. 通过设置layer的属性
最简单的一种,但是很影响性能,一般在正常的开发中使用很少.
self.button.layer.cornerRadius =30;
self.button.layer.masksToBounds= YES;
2.使用贝塞尔曲线UIBezierPath和Core Graphics 使用不多
貌似只能使用ImageView 这个不太懂
UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100,100,100,100)];
imageView.center=self.view.center;
imageView.image= [UIImage imageNamed:@"1"];//开始对imageView进行画图UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, NO, [UIScreen mainScreen].scale);//使用贝塞尔曲线画出一个圆形图[[UIBezierPath bezierPathWithRoundedRect:imageView.bounds cornerRadius:imageView.frame.size.width] addClip];
[imageView drawRect:imageView.bounds];
imageView.image=UIGraphicsGetImageFromCurrentImageContext();
UIImage*image =UIGraphicsGetImageFromCurrentImageContext();
[self.button setImage:image forState:UIControlStateNormal];//结束画图UIGraphicsEndImageContext();
[self.view addSubview:imageView];
3.使用CAShapeLayer和UIBezierPath设置圆角
// 只切一个角// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds byRoundingCorners:UIRectCornerTopLeft cornerRadii:self.button.bounds.size]; // 只切两个角// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(10, 10)]; // 注意 当size是整个大小时 切角是对角线会切成圆 size不是整个视图大小不会成圆角有人说必须导入我是没有发现 如果不行可以导入试试
// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerBottomRight cornerRadii:self.button.bounds.size];
// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerBottomRight cornerRadii:CGSizeMake(10, 10)];
// 三个角
// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerBottomRight | UIRectCornerTopRight cornerRadii:CGSizeMake(30, 30)];
// 四个角
// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds byRoundingCorners:UIRectCornerAllCorners cornerRadii:self.button.bounds.size];
// UIBezierPath *maskPAth = [UIBezierPath bezierPathWithRoundedRect:self.button.bounds cornerRadius:10];
// CAShapeLayer *caShapeLayer = [CAShapeLayer layer];
// caShapeLayer.path = maskPAth.CGPath;
// self.button.layer.mask = caShapeLayer;
这三种方法中第三种最好，对内存的消耗最少啊，而且渲染快速。
注意：这三种方法都是显示的是圆角，并不是真实切除角，在debug viewhierarchy上可以看出大小不变 显示改变
