2.23 Creating Scrollable Content with UIScrollView

来源：互联网发布：最优化导论中文版编辑：程序博客网时间：2024/04/27 10:21

他是一个UIView，你可以像对待UIView一样对待它。
你需要特别注意的是他的contentSize 属性，如果没设置好，他将不会滚屏(contentSize应该大于UIScrollView 的size)。

UIScrollViewDelegate 滚动代理

scrollViewDidScroll:当被滚动了就会触发，也就是在滚动过程中会一直触发的
scrollViewWillBeginDecelerating:开始减速，在手机离开屏幕时触发
scrollViewDidEndDecelerating: 结束减速，滚动停止时触发，结束滚屏
scrollViewDidEndDragging:willDecelerate:结束拖拽，这个方法有些像结束滚屏。区别：滚屏是那种，手指快速划一下，然后让屏幕滚一会的那种；拖拽就是把显示的内容拖过来一点，没有让屏幕滚的。

试了几个消息代理，做了一次滚屏操作，触发顺序如下

2013-11-11 10:08:45.478 SingleViewWithOutStoryboards[437:c07] will Begin Dragging
2013-11-11 10:08:45.481 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.494 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.512 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.517 SingleViewWithOutStoryboards[437:c07] Will End Dragging
2013-11-11 10:08:45.517 SingleViewWithOutStoryboards[437:c07] Did End Dragging
2013-11-11 10:08:45.518 SingleViewWithOutStoryboards[437:c07] Will Begin Decelerating
2013-11-11 10:08:45.535 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.552 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.569 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.586 SingleViewWithOutStoryboards[437:c07] Did Scroll
2013-11-11 10:08:45.602 SingleViewWithOutStoryboards[437:c07] Did Scroll
......
2013-11-11 10:08:47.319 SingleViewWithOutStoryboards[437:c07] Did End Decelerating

不过有时在找联系人时，会用力一划，滚到快到那个联系人了，赶紧按住。试了一下，结果如下
2013-11-11 10:27:19.533 SingleViewWithOutStoryboards[481:c07] will Begin Dragging
2013-11-11 10:27:19.534 SingleViewWithOutStoryboards[481:c07] Did Scroll
2013-11-11 10:27:19.541 SingleViewWithOutStoryboards[481:c07] Will End Dragging
2013-11-11 10:27:19.542 SingleViewWithOutStoryboards[481:c07] Did End Dragging
2013-11-11 10:27:19.542 SingleViewWithOutStoryboards[481:c07] Will Begin Decelerating
2013-11-11 10:27:19.560 SingleViewWithOutStoryboards[481:c07] Did Scroll
2013-11-11 10:27:19.577 SingleViewWithOutStoryboards[481:c07] Did Scroll
2013-11-11 10:27:19.593 SingleViewWithOutStoryboards[481:c07] Did Scroll
......
2013-11-11 10:27:19.902 SingleViewWithOutStoryboards[481:c07] will Begin Dragging
2013-11-11 10:27:20.830 SingleViewWithOutStoryboards[481:c07] Will End Dragging
2013-11-11 10:27:20.831 SingleViewWithOutStoryboards[481:c07] Did End Dragging
2013-11-11 10:27:20.844 SingleViewWithOutStoryboards[481:c07] Did End Decelerating

滚动条样式
indicatorStyle

typedef NS_ENUM(NSInteger, UIScrollViewIndicatorStyle) {
    UIScrollViewIndicatorStyleDefault,     // black with white border. good against any background
    UIScrollViewIndicatorStyleBlack,       // black only. smaller. good against a white background
    UIScrollViewIndicatorStyleWhite        // white only. smaller. good against a black background
};

翻页
pagingEnabled boolean
我们在浏览照片的时候，会翻页一张一张的看，pagingEnabled 就是用来指定要实现这样的效果。