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];
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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: