iOS自定义collectionView实现毛玻璃效果

// viewController@interface ViewController ()@property (nonatomic, strong) AXECollectionView *collectionView;@end@implementation ViewController- (void)viewDidLoad {  [super viewDidLoad];  // 流水布局  UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];  flowLayout.minimumLineSpacing = kItem_Margin;  flowLayout.minimumInteritemSpacing = [UIScreen mainScreen].bounds.size.height;  flowLayout.itemSize = CGSizeMake([UIScreen mainScreen].bounds.size.width - kItem_Margin, kItem_Height);  flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;  flowLayout.sectionInset = UIEdgeInsetsMake(0, kItem_Margin / 2, 0, kItem_Margin / 2);  CGRect frame = self.view.bounds;  _collectionView = [[AXECollectionView alloc] initWithFrame:frame collectionViewLayout:flowLayout];  // 传入图片数组  _collectionView.imgArr = @[                @"0",                @"1",                @"2",                @"3",                @"4",                @"5",                @"6",                @"7",                ];  [self.view addSubview:_collectionView];}// AXECollectionView.h@interface AXECollectionView : UICollectionView@property (nonatomic, strong) NSArray *imgArr;@end// AXECollectionView.m@interface AXECollectionView () <UICollectionViewDelegate, UICollectionViewDataSource>// 背景imgView@property (nonatomic, strong) UIImageView *bgImgView;@end@implementation AXECollectionViewstatic NSString *const AXECollectionViewCellID = @"AXECollectionViewCell";- (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout{  if(self = [super initWithFrame:frame collectionViewLayout:layout])  {    [self setup];  }  return self;}- (void)setup{  self.showsVerticalScrollIndicator = NO;  self.showsHorizontalScrollIndicator = NO;  self.pagingEnabled = YES;  self.dataSource = self;  self.delegate = self;  [self registerClass:[AXECollectionViewCell class] forCellWithReuseIdentifier:AXECollectionViewCellID];  // collectionView背景view  UIImageView *bgImgView = [[UIImageView alloc] initWithFrame:self.bounds];  self.backgroundView = bgImgView;  self.bgImgView = bgImgView;  // 毛玻璃效果 (iOS8.0以后适用)  UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];  UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];  effectView.frame = self.bounds;  [self.backgroundView addSubview:effectView];}#pragma mark - UICollectionViewDataSource- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{  AXECollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:AXECollectionViewCellID forIndexPath:indexPath];  cell.img = self.imgArr[indexPath.row];  // 设置毛玻璃图片  self.bgImgView.image = [UIImage imageNamed:self.imgArr[indexPath.row]];  return cell;}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{  return self.imgArr.count;}#pragma mark - UICollectionViewDelegate- (void)collectionView:(UICollectionView *)collectionView willDisplayCell:(UICollectionViewCell *)cell forItemAtIndexPath:(NSIndexPath *)indexPath{  AXECollectionViewCell *myCell = (AXECollectionViewCell *)cell;  [UIView animateWithDuration:0.5 animations:^{    myCell.transform = CGAffineTransformScale(CGAffineTransformIdentity, 1.0, 1.4);  }];}

// 返回滤镜处理后图片- (UIImage *)coreBlurImage:(UIImage *)image withBlurNumber:(CGFloat)blur{  CIContext *context = [CIContext contextWithOptions:nil];  CIImage *inputImage= [CIImage imageWithCGImage:image.CGImage];  // 设置filter  CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];  [filter setValue:inputImage forKey:kCIInputImageKey];  [filter setValue:@(blur) forKey: @"inputRadius"];  // 模糊图片  CIImage *result=[filter valueForKey:kCIOutputImageKey];  CGImageRef outImage=[context createCGImage:result fromRect:[result extent]];  UIImage *blurImage=[UIImage imageWithCGImage:outImage];  CGImageRelease(outImage);  return blurImage;}// 返回高斯效果模糊图片- (UIImage *)boxblurImage:(UIImage *)image withBlurNumber:(CGFloat)blur{  if (blur < 0.f || blur > 1.f) {    blur = 0.5f;  }  int boxSize = (int)(blur * 40);  boxSize = boxSize - (boxSize % 2) + 1;  CGImageRef img = image.CGImage;  vImage_Buffer inBuffer, outBuffer;  vImage_Error error;  void *pixelBuffer;  // 从CGImage中获取数据  CGDataProviderRef inProvider = CGImageGetDataProvider(img);  CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);  // 设置从CGImage获取对象的属性  inBuffer.width = CGImageGetWidth(img);  inBuffer.height = CGImageGetHeight(img);  inBuffer.rowBytes = CGImageGetBytesPerRow(img);  inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);  pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));  if(pixelBuffer == NULL)    NSLog(@"No pixelbuffer");  outBuffer.data = pixelBuffer;  outBuffer.width = CGImageGetWidth(img);  outBuffer.height = CGImageGetHeight(img);  outBuffer.rowBytes = CGImageGetBytesPerRow(img);  error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);  if (error) {    NSLog(@"error from convolution %ld", error);  }  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();  CGContextRef ctx = CGBitmapContextCreate( outBuffer.data, outBuffer.width, outBuffer.height, 8, outBuffer.rowBytes, colorSpace, kCGImageAlphaNoneSkipLast);  CGImageRef imageRef = CGBitmapContextCreateImage (ctx);  UIImage *returnImage = [UIImage imageWithCGImage:imageRef];  // clean up  CGColorSpaceRelease(colorSpace);  free(pixelBuffer);  CFRelease(inBitmapData);  CGColorSpaceRelease(colorSpace);  CGImageRelease(imageRef);  return returnImage;}