图片快速向下滑动取消的时候,页面会闪烁一下,慢慢滑动没有这个问题. about xlimageviewer

[lvpeng0412]

• (void)scrollViewDidScroll:(UIScrollView *)scrollView {

  /if (ABS(_scrollView.contentOffset.y) < minPanLength) {
  CGFloat alpha = 1 - ABS(_scrollView.contentOffset.y / (_scrollView.bounds.size.height));
  _collectionView.backgroundColor = [UIColor colorWithWhite:0 alpha:alpha];
  }/
  }

• (void)scrollViewPanMethod:(UIPanGestureRecognizer *)pan {
  if (_scrollView.zoomScale != 1.0f) {return;}
  if (_scrollView.contentOffset.y > 0) {
  _cancleideBlock();
  return;
  }
  //拖拽结束后判断位置
  if (pan.state == UIGestureRecognizerStateEnded) {
  if (ABS(_scrollView.contentOffset.y) < minPanLength) {
  _cancleideBlock();
  [UIView animateWithDuration:0.35 animations:^{
  _## collectionView.backgroundColor = [UIColor colorWithWhite:0 alpha:1];
  _scrollView.contentInset = UIEdgeInsetsZero;
  }];
  } else {
  [UIView animateWithDuration:0.35 animations:^{
  //设置移除动画
  CGRect frame = _imageView.frame;
  frame.origin.y = _scrollView.bounds.size.height;
  _imageView.frame = frame;
  _collectionView.backgroundColor = [UIColor colorWithWhite:0 alpha:0];
  } completion:^(BOOL finished) {
  //先通知上层返回
  _finishHideBlock();
  //重置状态
  _imageView.frame = [self imageViewFrame];
  _scrollView.contentInset = UIEdgeInsetsZero;
  }];
  }
  } else {
  //拖拽过程中逐渐改变透明度
  _scrollView.contentInset = UIEdgeInsetsMake(-_scrollView.contentOffset.y, 0, 0, 0);
  CGFloat alpha = 1 - ABS(_scrollView.contentOffset.y / (_scrollView.bounds.size.height));
  _collectionView.backgroundColor = [UIColor colorWithWhite:0 alpha:alpha];
  _startHideBlock();
  }
  }

[lvpeng0412]

scrollViewDidScroll 里面的代码可以去掉，
下面加一行
_collectionView.backgroundColor = [UIColor colorWithWhite:0 alpha:1];
就可以修复这个问题

好的 谢谢