iOS 9宫格切割图像

实现效果前

屏幕快照 2017-06-05 下午5.32.59.png

实现效果后

屏幕快照 2017-06-05 下午5.33.13.png
一.首先要做如果切割图片，切割图片的代码如下：

- (UIImage *)captureView:(UIView *)theView frame:(CGRect)fra {

        UIGraphicsBeginImageContext(theView.frame.size);
        CGContextRef context = UIGraphicsGetCurrentContext();
        [theView.layer renderInContext:context];
        UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        CGImageRef ref = CGImageCreateWithImageInRect(img.CGImage, fra);
        UIImage *i = [UIImage imageWithCGImage:ref];
        CGImageRelease(ref);
        return i;

}

二.点击切图前，用UIImageView把图片加载出来（切割前的效果）：

- (void)viewDidLoad {

        [super viewDidLoad];
        UIImage *image = [UIImage imageNamed:@"image"];
        _bigImageView = [[UIImageView alloc]initWithFrame:CGRectMake(30, 100, 315,315/image.size.width*image.size.height )];
        _bigImageView.image = image;
        [self.view addSubview:_bigImageView];

}

三.点击切图：
把图片切成九宫格，就是横着切3段，竖着切3段，2个for循环，对已知image进行切割。切割的rect：CGRectMake(jself.bigImageView.frame.size.width1.0/3,iself.bigImageView.frame.size.height1.0/3,self.bigImageView.frame.size.width1.0/3,self.bigImageView.frame.size.height1.0/3)不要搞错，获得9张图片的数组。

- (void)captureImageArr {
        self.imageArr = [[NSMutableArray alloc]init];
        for (int i = 0; i < 3; i++) {
                for (int j = 0; j<3; j++) {
                        UIImage *theImage = [self captureView:self.bigImageView     frame:CGRectMake(j*self.bigImageView.frame.size.width*1.0/3,i*self.bigImageView.frame.size.height*1.0/3,self.bigImageView.frame.size.width*1.0/3,self.bigImageView.frame.size.height*1.0/3)];
                        [self.imageArr addObject:theImage];
                }
         }
}

四.将获得的数组用UICollectionView接收，组成9宫格

五.完整代码如下

static NSString *const cellId = @"cellId";

@interface ViewController ()

@property (nonatomic,strong)UICollectionView *collectionView;

@property (nonatomic,strong) UIImageView *bigImageView;

@property (nonatomic,strong) NSMutableArray *imageArr;

@end

@implementation ViewController

- (void)viewDidLoad {    

[super viewDidLoad]; 

UIImage *image = [UIImage imageNamed:@"image"];   

 _bigImageView = [[UIImageView alloc]initWithFrame:CGRectMake(30, 100, 315,315/image.size.width*image.size.height )];    

_bigImageView.image = image;    [self.view addSubview:_bigImageView];

}

- (void)captureImageArr {    

self.imageArr = [[NSMutableArray alloc]init];   

 for (int i = 0; i < 3; i++) {        

      for (int j = 0; j<3; j++) {            

UIImage *theImage = [self captureView:self.bigImageView frame:CGRectMake(j*self.bigImageView.frame.size.width*1.0/3,i*self.bigImageView.frame.size.height*1.0/3,self.bigImageView.frame.size.width*1.0/3,self.bigImageView.frame.size.height*1.0/3)];                     

[self.imageArr addObject:theImage];            

  }    }}

- (UIImage *)captureView:(UIView *)theView frame:(CGRect)fra {    

UIGraphicsBeginImageContext(theView.frame.size);    

CGContextRef context = UIGraphicsGetCurrentContext();    

[theView.layer renderInContext:context];    

UIImage *img = UIGraphicsGetImageFromCurrentImageContext();   

 UIGraphicsEndImageContext();    

CGImageRef ref = CGImageCreateWithImageInRect(img.CGImage, fra);    

UIImage *i = [UIImage imageWithCGImage:ref];   

 CGImageRelease(ref);    

return i;                            

}

- (IBAction)CutAction:(id)sender {

[self captureImageArr];

//此处必须要有创见一个UICollectionViewFlowLayout的对象

UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc]init];

//同一行相邻两个cell的最小间距

layout.minimumInteritemSpacing = 5;

//最小两行之间的间距

layout.minimumLineSpacing = 5;

_collectionView = [[UICollectionView alloc] initWithFrame:_bigImageView.frame collectionViewLayout:layout];

[_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:cellId];

_collectionView.backgroundColor = [UIColor whiteColor];

_collectionView.dataSource = self;

_collectionView.delegate = self;

_collectionView.backgroundColor = [UIColor yellowColor];

[self.view addSubview:_collectionView];

}

#pragma mark ---- UICollectionViewDataSource

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView

{

return 1;

}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

{

return 9;

}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

UICollectionViewCell *cell = [_collectionView dequeueReusableCellWithReuseIdentifier:cellId forIndexPath:indexPath];

UIImageView *imageView = [[UIImageView alloc]initWithFrame:cell.contentView.frame];

imageView.image = self.imageArr[indexPath.row];

[cell.contentView addSubview:imageView];

return cell;

}

//定义每一个cell的大小

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath

{

return CGSizeMake((self.bigImageView.frame.size.width-10)/3, (self.bigImageView.frame.size.height-10)/3);

}

//cell的点击事件

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{

//cell被点击后移动的动画

[collectionView selectItemAtIndexPath:indexPath animated:YES scrollPosition:UICollectionViewScrollPositionTop];

}

@end