底部导航上拉出现,下拉消失

标签：

条件一:全局变量 CGFloat _scrollviewBeginSet;

    CGFloat _scrollviewDidSet;

 条件二:代理方法

- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView {

    _scrollviewBeginSet = scrollView.contentOffset.y;

}

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {

    _scrollviewDidSet = 0;

}

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

    if (_scrollviewDidSet == 0) {

        _scrollviewDidSet = scrollView.contentOffset.y;

        if (_scrollviewBeginSet < _scrollviewDidSet) {

            [UIView animateWithDuration:.25 animations:^{

                barBgView.transform = CGAffineTransformMakeTranslation(0,barBgView.height);

            }];

        } else {

            [UIView animateWithDuration:.25 animations:^{

                barBgView.transform = CGAffineTransformMakeTranslation(0,-barBgView.height);

            }];

        }

    }

}

底部导航上拉出现,下拉消失

标签：

原文地址：http://www.cnblogs.com/yr434/p/4953669.html