iOS设置圆角的三种方式

转载：https://www.cnblogs.com/mafeng/p/5672528.html

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。

第一种方法:通过设置layer的属性转最简单的一种,但是很影响性能,一般在正常的开发中使用很少.

UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];

//只需要设置layer层的两个属性

//设置圆角

imageView.layer.cornerRadius = imageView.frame.size.width / 2;//将多余的部分切掉imageView.layer.masksToBounds = YES;

[self.view addSubview:imageView];

第二种方法:使用贝塞尔曲线UIBezierPath和Core Graphics框架画出一个圆角

UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];imageView.image = [UIImage imageNamed:@"1"];

//开始对imageView进行画图

UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, NO, 1.0);

//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();//结束画图

UIGraphicsEndImageContext();

[self.view addSubview:imageView];

第三种方法:使用CAShapeLayer和UIBezierPath设置圆角首先需要导入

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];

imageView.image = [UIImage imageNamed:@"1"];

UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:imageView.bounds byRoundingCorners:UIRectCornerAllCorners cornerRadii:imageView.bounds.size];

CAShapeLayer *maskLayer = [[CAShapeLayer alloc]init];

//设置大小

maskLayer.frame = imageView.bounds;

//设置图形样子

maskLayer.path = maskPath.CGPath;

imageView.layer.mask = maskLayer;

[self.view addSubview:imageView];

}