當(dāng)viewController中只有一個scrollView時，點擊statusBar，該scrollView就會滾動到頂部，但當(dāng)viewController中有多個scrollView時，這個功能就失效了。

為什么呢？UIScrollView有個屬性 ，叫scrollsToTop，看下官方注解：

“When the user taps the status bar, the scroll view beneath the touch which is closest to the status bar will be scrolled to top, but only if its `scrollsToTop` property is YES, its delegate does not return NO from `shouldScrollViewScrollToTop`, and it is not already at the top.

On iPhone, we execute this gesture only if there's one on-screen scroll view with `scrollsToTop` == YES. If more than one is found, none will be scrolled.”

@property?(nonatomic)?BOOL?scrollsToTop ?__TVOS_PROHIBITED;?// default is YES.

可以看到，點擊statusBar時如果發(fā)現(xiàn)有多個scrollView時就不會有滾動效果了。

解決辦法很簡單，把需要有滾動效果的scrollView的scrollsToTop屬性設(shè)為YES，其他的設(shè)為NO，也就是說同一時間內(nèi)只能讓一個scrollView的scrollsToTop屬性為YES。