UIScrollViewDelegate
1.方法
Responding to Scrolling and Dragging
– scrollViewDidScroll:
– scrollViewWillBeginDragging:
– scrollViewWillEndDragging:withVelocity:targetContentOffset:
– scrollViewDidEndDragging:willDecelerate:
– scrollViewShouldScrollToTop:
– scrollViewDidScrollToTop:
– scrollViewWillBeginDecelerating:
– scrollViewDidEndDecelerating:
Managing Zooming
– viewForZoomingInScrollView:
– scrollViewWillBeginZooming:withView:
– scrollViewDidEndZooming:withView:atScale:
– scrollViewDidZoom:
Responding to Scrolling Animations
– scrollViewDidEndScrollingAnimation:
2.测试
2.1 普通上拉和下拉,超出scroller本身的界面那种拉动,代理调用顺序:
scrollViewWillBeginDragging //开始滑动
scrollViewDidScroll
…
scrollViewDidScroll
scrollViewWillEndDragging
scrollViewDidEndDragging //结束滑动
scrollViewWillBeginDecelerating //开始回弹,减速
scrollViewDidScroll
…
scrollViewDidScroll
scrollViewDidEndDecelerating //减速结束,停止回到原位
2.2界面内的滑动,未触及上下底部,代理调用顺序:
scrollViewWillBeginDragging //开始滑动
scrollViewDidScroll
…
scrollViewDidScroll
scrollViewWillEndDragging
scrollViewDidEndDragging //结束滑动
2.3 scroller属性,scrollsToTop,当值为YES的时候,点击status bar,则scroller回到顶部,代理调用顺序:
scrollViewShouldScrollToTop //点击status bar
scrollViewDidScroll
…
scrollViewDidScroll
scrollViewDidScrollToTop //回到顶部
3.疑问:
scrollViewWillEndDragging:withVelocity:targetContentOffset 方法,文档说当 scroller的pagingEnabled为YES的时候,不会调用,但是测试发现,是调用的,原因待查