判断TableView滚动到底部

-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
    
    CGFloat height = scrollView.frame.size.height;
    CGFloat contentYoffset = scrollView.contentOffset.y;
    CGFloat distanceFromBottom = scrollView.contentSize.height - contentYoffset;
    
    if (distanceFromBottom < height) {
        NSLog(@"滑到底了");
    }
    
}