一.正常圆角的实现
在做项目过程中，我们总会遇到实现圆角的情况
1.通过layer来实现
- (UIImageView *)testImageView
{
if (_testImageView) {
_testImageView = [[UIImageView alloc] init];
_testImageView.layer.cornerRadius = 5.0; // 圆角
_testImageView.layer.masksToBounds = YES; // 切掉多余的地方
}
return _testImageView;
}
2.通过GPU来做
//
// UIImage+GetCornerRadius.m
// GetCornerRadius
//
// Created by Cyrill on 16/8/18.
// Copyright © 2016年 Cyrill. All rights reserved.
//
#import "UIImage+GetCornerRadius.h"
@implementation UIImage (GetCornerRadius)
//圆角切割
- (UIImage *)cy_getCornerRadius:(CGFloat)cornerRadius
{
CGFloat scale = [UIScreen mainScreen].scale;
UIGraphicsBeginImageContextWithOptions(self.size, NO, scale);
CGContextRef c = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:cornerRadius];
CGContextAddPath(c, path.CGPath);
CGContextClip(c);
[self drawInRect:rect];
CGContextDrawPath(c, kCGPathFillStroke);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
@end
这样会返回一个已经切割好的图片。好处是用GPU来处理圆角效果,一些情况下会提升app的性能。
