- (void)scrollViewDidScroll:(UIScrollView *)aScrollView {
CGPoint offset = aScrollView.contentOffset; CGRect bounds = aScrollView.bounds; CGSize size = aScrollView.contentSize; UIEdgeInsets inset = aScrollView.contentInset; float y = offset.y + bounds.size.height - inset.bottom; float h = size.height; float reload_distance = -20; if(y > h + reload_distance) { //距离到底 20 像素 } }}