Segment 滑动

- (void)lineViewScrollToIndex:(NSInteger)index {    [UIView animateWithDuration:0.3 animations:^{        self.lineView.x = index*self.lineView.width;    }completion:^(BOOL finished) {        CGPoint point = self.baseScrollView.contentOffset;        CGPoint lineViewToSelfPoint = [self.lineView.superview convertPoint:self.lineView.center toView:self];        //把当前的滑动到中心点的距离        CGFloat toScrollViewCenter = lineViewToSelfPoint.x - self.center.x;        if (toScrollViewCenter <0) {//要向右边滑动contentOffset.x >=0            // 这里表示scrollView向右滑动            point.x += toScrollViewCenter;            // 但是向右滑动不能小于0，否则将会出现第一个 也向右偏移            if (point.x <0) {                point.x = 0;            }        }else {//向左滑动 contentOffset.x <= relationValue            //这里表示向左滑动            //这个是最大的偏移X量            CGFloat maxOffX = self.baseScrollView.contentSize.width - self.baseScrollView.width;            point.x += toScrollViewCenter;            // 如果向左滑动超出了它的最大偏移量            if (point.x>maxOffX) {                point.x = maxOffX;            }        }        [self.baseScrollView setContentOffset:point animated:YES];    }];}