滚动滚动视图隐藏显示导航栏效果

方法一 根据滚动速度显示或隐藏效果

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

  UIPanGestureRecognizer *pan = scrollView.panGestureRecognizer;
  //获取到拖拽的速度 >0 向下拖动 <0 向上拖动
  CGFloat velocity = [pan velocityInView:scrollView].y;

  [UIView animateWithDuration:1.5f animations:^{
  //向上拖动，隐藏导航栏
  if (velocity < -5) {
  self.rcsPersonDetailInfoViewControllerNavigationBarView.hidden = YES;
  //向下拖动，显示导航栏
  }else if (velocity > 5){
  self.rcsPersonDetailInfoViewControllerNavigationBarView.hidden = NO;
  }else if(velocity == 0){

    }
  

  } completion:^(BOOL finished) {

  }];
  }
  方法二 根据滚动偏移量
  -(void)scrollViewDidScroll:(UIScrollView *)scrollView{
  //获取偏移
  CGFloat offsetY = scrollView.contentOffset.y + self.rcsPersonInfoTableView.contentInset.top;
  CGFloat panTranslationY = [scrollView.panGestureRecognizer translationInView:self.rcsPersonInfoTableView].y;
  if (offsetY > 200) {
  if (panTranslationY > 0) {
  //下滑趋势，显示
  [UIView animateWithDuration:1.5f animations:^{
  self.rcsPersonDetailInfoViewControllerNavigationBarView.hidden = NO;
  }];
  //向上拖动，隐藏导航栏
  }else if(panTranslationY < 0){

        [UIView animateWithDuration:1.5f animations:^{
            self.rcsPersonDetailInfoViewControllerNavigationBarView.hidden = YES;
        }];
    }
  

  }else{

    self.rcsPersonDetailInfoViewControllerNavigationBarView.hidden = NO;
  

  }
  }