tableView向上向下滚动时，段头视图做出改变

Question

• (void)scrollViewDidScroll:(UIScrollView *)scrollView
  {
  NSLog(@"%lf",scrollView.contentOffset.y);
  NSInteger m = scrollView.contentOffset.y;
  if ( m >= 0 )
  {
  UIView *view = (UIView *)[self.view viewWithTag:100];
  view.backgroundColor = [UIColor colorWithRed:234/255.0 green:234/255.0 blue:234/255.0 alpha:0.5];

  }
  现在向下是可以了，但是向上的时候没有效果啊

Answer 1

http://www.cocoachina.com/bbs/read.php?tid=336018