iOS设置圆角的三种方式

第一种方法: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.

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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

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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

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(, , , )];
    imageView.image = [UIImage imageNamed:@""];
    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:imageView.bounds byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerTopLeft cornerRadii:CGSizeMake(, )];
    CAShapeLayer *maskLayer = [[CAShapeLayer alloc]init];
    maskLayer.frame = imageView.bounds;
    maskLayer.path = maskPath.CGPath;
    imageView.layer.mask = maskLayer;
    [self.view addSubview:imageView];
}

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。

效果图: