iphone - UIScrollView可以zoomToRect吗？

Question

有没有一种方法可以确定UIScrollView是否可以在zoomToRect:和maximumZoomScale中使用minimumZoomScale？因此，如果所需的zoomScale太小，则返回NO？

Answer 1

也许这种事情可能起作用？ (从https://stackoverflow.com/a/2125472/845115偷来的想法)

- (BOOL)scrollView:(UIScrollView*)scrollView canZoomToRect:(CGRect)zoomToRect {
    CGPoint contentOffsetBefore = scrollView.contentOffset;
    CGFloat zoomBefore = scrollView.zoomScale;
    [scrollView zoomToRect:zoomToRect animated:NO];
    CGFloat zoomAfter = scrollView.zoomScale;

    [scrollView setZoomScale:zoomBefore animated:NO];
    [scrollView setContentOffset:contentOffsetBefore animated:NO];

    return (zoomBefore == zoomAfter);
}