iOS视图切割圆角

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