Lock scroll view scroll to horizontal or vertical direction

Lock scroll view scroll to horizontal or vertical direction

scrollView.directionalLockEnabled still allows diagonal scrolling.
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    self.initialOffeset = scrollView.contentOffset;
}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    //lock scroll direction
    CGFloat xdis = scrollView.contentOffset.x - self.initialOffeset.x;
    CGFloat ydis = scrollView.contentOffset.y - self.initialOffeset.y;
    if (fabs(xdis) >= fabs(ydis))
    {
        scrollView.contentOffset = CGPointMake(scrollView.contentOffset.x, self.initialOffeset.y);
    }
    else
    {
        scrollView.contentOffset = CGPointMake(self.initialOffeset.x, scrollView.contentOffset.y);
    }
}