简单图片裁剪

Posted on 2016-07-04 18:07  柠檬片  阅读(145)  评论(0)    收藏  举报 
  1 #import "ViewController.h"
  2 
  3 @interface ViewController ()
  4 @property (weak, nonatomic) IBOutlet UIImageView *imageView;
  5 
  6 @end
  7 
  8 @implementation ViewController
  9 //点击裁剪 按钮事件
 10 - (IBAction)clipBtnClick:(id)sender
 11 {
 12     //1.加载要裁剪的图片
 13     UIImage * image = [UIImage imageNamed:@"dst2"];
 14     
 15     //2.开启一个图形上下文 (bitmap  大小和要裁剪的图片大小一样)
 16     UIGraphicsBeginImageContextWithOptions(image.size, NO, 0.0);
 17     
 18     //3.获取图形上下文
 19     CGContextRef ctx = UIGraphicsGetCurrentContext();
 20     
 21     //4.创建路径
 22     //设置圆心
 23     CGPoint centerP = CGPointMake(image.size.width/2, image.size.height/2);
 24     //设置半径
 25     CGFloat radius = MIN(image.size.width, image.size.height)/2;
 26     
 27     UIBezierPath * path = [UIBezierPath bezierPathWithArcCenter:centerP radius:radius startAngle:0 endAngle:2 * M_PI clockwise:YES];
 28     
 29     //5.把路径添加到图形上下文中
 30     CGContextAddPath(ctx, path.CGPath);
 31     
 32     //6.执行裁剪
 33     CGContextClip(ctx);
 34     
 35     
 36     //7.绘制图片
 37     [image drawAtPoint:CGPointZero];
 38     
 39     //8.获取图片
 40     UIImage * getImage = UIGraphicsGetImageFromCurrentImageContext();
 41     
 42     //8.1 结束图形上下文
 43     UIGraphicsEndImageContext();
 44     
 45     //8.2 裁剪图片
 46     //其中x,y需要根据实际情况计算
 47     CGFloat x = 0;
 48     CGFloat y = (image.size.height - 2 * radius)/2;
 49     
 50     CGFloat w = 2 * radius;
 51     CGFloat h = w;
 52     
 53     //获取屏幕的缩放比
 54     CGFloat scale = [UIScreen mainScreen].scale;
 55     x *= scale;
 56     y *= scale;
 57     
 58     w *= scale;
 59     h *= scale;
 60     
 61     CGImageRef imageRef = CGImageCreateWithImageInRect(getImage.CGImage, CGRectMake(x, y, w, h));
 62     
 63     //获取裁剪后的图片
 64     getImage = [UIImage imageWithCGImage:imageRef];
 65     
 66     self.imageView.image = getImage;
 67     
 68     //9.保存
 69     
 70     //9.1 保存相册
 71     UIImageWriteToSavedPhotosAlbum(getImage, self, @selector(image:didFinishSavingWithError:contextInfo:), @"hello word");
 72     //9.2 保存沙盒
 73     
 74     NSString * documents = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
 75     
 76     //拼接文件名
 77     NSString * fileName = [documents stringByAppendingPathComponent:@"001.png"];
 78     
 79     //把UIimage--->NSData
 80     NSData * imageData = UIImagePNGRepresentation(getImage);
 81     
 82     [imageData writeToFile:fileName atomically:YES];
 83     
 84     NSLog(@"%@",fileName);
 85 }
 86 //保存相册方法
 87 - (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
 88 {
 89     NSLog(@"保存完毕 %@",contextInfo);
 90 }
 91 
 92 - (void)savePhoto
 93 {
 94     NSLog(@"保存完毕");
 95 }
 96 - (void)viewDidLoad {
 97     [super viewDidLoad];
 98     // Do any additional setup after loading the view, typically from a nib.
 99 }
100 
101 - (void)didReceiveMemoryWarning {
102     [super didReceiveMemoryWarning];
103     // Dispose of any resources that can be recreated.
104 }
105 
106 @end
简单裁剪并保存