iOS设置圆角的三种方式(禁用layer)

第一种方法:通过设置layer的属性 

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];

 注：禁用。。影响性能。

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<AVFoundation/AVFoundation.h>

#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];

}