UIView * viewContainer = [[UIView alloc] initWithFrame: CGRectMake(0, 0, 200, 200)];
viewContainer.backgroundColor = [UIColor blueColor];

UIView * contentView = [[UIView alloc] initWithFrame: CGRectMake(20, 20, 160, 160)];
contentView.backgroundColor = [UIColor redColor];
[viewContainer addSubview: contentView];

UIView * maskView = [[UIView alloc] initWithFrame: CGRectMake(100, 100, 35, 80)];
maskView.backgroundColor = [UIColor yellowColor];
contentView.maskView = maskView;

maskView.backgroundColor = [UIColor colorWithWhite: 1 alpha: 0.5]; //任意颜色

maskView.backgroundColor = [UIColor clearColor];
UIView * sub1 = [[UIView alloc] initWithFrame: CGRectMake(0, 0, 20, 34)];
sub1.backgroundColor = [UIColor blackColor];
UIView * sub2 = [[UIView alloc] initWithFrame: CGRectMake(15, 18, 33, 40)];
sub2.backgroundColor = [UIColor blackColor];
[maskView addSubview: sub1];
[maskView addSubview: sub2];

UIView * maskView = [[UIView alloc] initWithFrame: contentView.bounds];
const NSInteger horizontalCount = 15;
const NSInteger verticalCount = 2;
const CGFloat fadeWidth = CGRectGetWidth(maskView.frame) / horizontalCount;
const CGFloat fadeHeight = CGRectGetHeight(maskView.frame) / verticalCount;

for (NSInteger line = 0; line < horizontalCount; line ++) {
  for (NSInteger row = 0; row < verticalCount; row++) {
    CGRect frame = CGRectMake(line*fadeWidth, row*fadeHeight, fadeWidth, fadeHeight);
    UIView * fadeView = [[UIView alloc] initWithFrame: frame];
    fadeView.tag = [self viewTag: line*verticalCount+row];
    fadeView.backgroundColor = [UIColor whiteColor];
    [maskView addSubview: fadeView];
  }
}
contentView.maskView = maskView;

for (NSInteger line = 0; line < horizontalCount; line ++) {
  for (NSInteger row = 0; row < verticalCount; row++) {
    NSInteger idx = line*verticalCount+row;
    UIView * fadeView = [contentView.maskView viewWithTag: [self viewWithTag: idx];
    [UIView animateWithDuration: fadeDuration delay: interval*idx options: UIViewAnimationOptionCurveLinear animations: ^{
      fadeView.alpha = 0;
    } completion: nil];
  }
}

#define LXDMAXDURATION 1.2
#define LXDMINDURATION .2
#define LXDMULTIPLED .25

@interface UIView (LXDFadeAnimation)

/*!
 * @brief 视图是否隐藏
 */
@property (nonatomic, assign, readonly) BOOL isFade;
/*!
 * @brief 是否处在动画中
 */
@property (nonatomic, assign, readonly) BOOL isFading;
/*!
 * @brief 垂直方块个数。默认为3
 */
@property (nonatomic, assign) NSInteger verticalCount;
/*!
 * @brief 水平方块个数。默认为18
 */
@property (nonatomic, assign) NSInteger horizontalCount;
/*!
 * @brief 方块动画之间的间隔0.2~1.2。默认0.7
 */
@property (nonatomic, assign) NSTimeInterval intervalDuration;
/*!
 * @brief 每个方块隐藏的动画时间0.05~0.3，最多为动画时长的25%。默认为0.175
 */
@property (nonatomic, assign) NSTimeInterval fadeAnimationDuration;

- (void)configurateWithVerticalCount: (NSInteger)verticalCount horizontalCount: (NSInteger)horizontalCount interval: (NSTimeInterval)interval duration: (NSTimeInterval)duration;

- (void)reverseWithComplete: (void(^)(void))complete;
- (void)animateFadeWithComplete: (void(^)(void))complete;
- (void)reverseWithoutAnimate;

@end

- (BOOL)isFade
{
  return [objc_getAssociatedObject(self, kIsFadeKey) boolValue];
}  
// other getAssociatedObject method

- (void)setIsFade: (BOOL)isFade
{
  objc_setAssociatedObject(self, kIsFadeKey, @(isFade), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
// other setAssociatedObject method

NSInteger fadeCount = self.verticalCount * self.horizontalCount;
for (NSInteger idx = fadeCount - 1; idx >= 0; idx--) {
  UIView * subview = [self.maskView viewWithTag: [self subViewTag: idx]];
  [UIView animateWithDuration: self.fadeAnimationDuration delay: self.intervalDuration * (fadeCount - 1 - idx) options: UIViewAnimationOptionCurveLinear animations: ^{
    subview.alpha = 1;
  } completion: nil];
}

__block NSInteger timeCount = 0;
//......
[UIView animateWithDuration: self.fadeAnimationDuration delay: self.intervalDuration * (fadeCount - 1 - idx) options: UIViewAnimationOptionCurveLinear animations: ^{
  subview.alpha = 1;
} completion: ^(BOOL finished) {
  if (++timeCount == fadeCount) {
    self.isFade = NO;
    self.isFading = NO;
    if (complete) { complete(); }
  }
}];
//......

// 获取动态绑定临时展示的UIImageView
- (UIImageView *)associateTempBannerWithImage: (UIImage *)image
{
  UIImageView * tempBanner = objc_getAssociatedObject(self, kTempImageKey);
  if (!tempBanner) {
    tempBanner = [[UIImageView alloc] initWithFrame: self.frame];
    objc_setAssociatedObject(self, kTempImageKey, tempBanner, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    [self.superview insertSubview: tempBanner belowSubview: self];
  }
  tempBanner.image = image;
  return tempBanner;
}

- (void)associatePageControlWithCurrentIdx: (NSInteger)idx
{
  UIPageControl * pageControl = objc_getAssociatedObject(self, kPageControlKey);
  if (!pageControl) {
    pageControl = [[UIPageControl alloc] initWithFrame: CGRectMake(self.frame.origin.x, CGRectGetHeight(self.frame) - 37 + self.frame.origin.y, CGRectGetWidth(self.frame), 37)];
    [self.superview addSubview: pageControl];
    pageControl.numberOfPages = self.bannerImages.count;
    objc_setAssociatedObject(self, kPageControlKey, pageControl, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
  }
  pageControl.currentPage = idx;
}

- (void)fadeBanner
  NSParameterAssert(self.superview);
  UIImageView * tempBanner = [self associateTempBannerWithImage: [UIImage imageNamed: self.bannerImages[1]]];
  self.stop = NO;
  __block NSInteger idx = 0;
  __weak typeof(self) weakSelf = self;
  [self associatePageControlWithCurrentIdx: idx];

  void (^complete)() = ^{
    NSInteger updateIndex = [weakSelf updateImageWithCurrentIndex: ++idx tempBanner: tempBanner];
    idx = updateIndex;
    [weakSelf associatePageControlWithCurrentIdx: idx];
  };
  // 保存block并执行动画
  objc_setAssociatedObject(self, kCompleteBlockKey, complete, OBJC_ASSOCIATION_COPY_NONATOMIC);
  [self animateFadeWithComplete: ^{
    if (!self.stop) {
      complete();
    }
  }];
}

// 更新展示的图片，并且返回下一次要展示的图片下标
- (NSInteger)updateImageWithCurrentIndex: (NSInteger)idx tempBanner: (UIImageView *)tempBanner
{
  if (idx >= self.bannerImages.count) { idx = 0; }
  self.image = [UIImage imageNamed: self.bannerImages[idx]];
  [self reverseWithoutAnimate];
  NSInteger nextIdx = idx + 1;
  if (nextIdx >= self.bannerImages.count) { nextIdx = 0; }
  tempBanner.image = [UIImage imageNamed: self.bannerImages[nextIdx]];
  [self animateFadeWithComplete: ^{
    if (!self.stop) {
      void (^complete)() = objc_getAssociatedObject(self, kCompleteBlockKey);
      complete();
    }
  }];
  return idx;
}

- (void)reverseWithoutAnimate
{
  if (self.isFading) {
    NSLog(@"It's animating!");
    return;
  }
  for (UIView * subview in self.maskView.subviews) {
    subview.alpha = 1;
  }
}