IOS UIScrollView 滚动视图的使用和文档

UIScrollView 是一个可滚动的视图列表，在app中非常常见。下面简单的介绍一下UIScrollView 的用法。可实现代理UIScrollViewDelegate

// 实例化UIScrollView
 UIScrollView* _scrollView = [[UIScrollView alloc] init];
    // 获取屏幕大小
    UIScreen* screen = [UIScreen mainScreen];
    // 设置滚动视图大小
    _scrollView.frame = CGRectMake(0, 0, screen.bounds.size.width, screen.bounds.size.height);
    // 设置滚动视图内容画布大小,当内容画布大小超过frame时候会出现滚动
    _scrollView.contentSize = CGSizeMake(screen.bounds.size.width, maxViewNum * screen.bounds.size.height);
    // 设置回弹效果
    _scrollView.bounces = YES;
    // 设置可滚动
    _scrollView.scrollEnabled = YES;
    // 设置显示Y轴滚地图
    _scrollView.showsVerticalScrollIndicator = YES;
    
    [self.view addSubview:_scrollView];

属性

名称	类型	说明	默认值
contentOffset	CGPoint	滚动视图内容当前滚动的位置	0,0
contentSize	CGSize	滚动视图内容当前大小
directionalLockEnabled	BOOL	滚动时候尝试锁定一个方向滚动	NO
bounces	BOOL	启用回弹效果	YES
alwaysBounceVertical	BOOL	始终启用垂直回弹效果	NO
alwaysBounceHorizontal	BOOL	始终启用水平回弹效果	NO
pagingEnabled	BOOL	翻页滚动模式	NO
scrollEnabled	BOOL	启动滚动	NO
showsVerticalScrollIndicator	BOOL	显示垂直滚动条	YES
showsHorizontalScrollIndicator	BOOL	显示水平滚动条	YES
indicatorStyle	UIScrollViewIndicatorStyle	滚动条样式	UIScrollViewIndicatorStyleDefault
indicatorStyle	UIScrollViewIndicatorStyle	滚动条样式	UIScrollViewIndicatorStyleDefault

API

• - (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated 使用动画设置滚动位置
• - (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated 使用动画滚动到指定矩形区域
• - (void)setZoomScale:(CGFloat)scale animated:(BOOL)animated 动画设置缩放
• - (void)zoomToRect:(CGRect)rect animated:(BOOL)animated 动画移动到指定矩形区域

代理协议函数

• - (void)scrollViewDidScroll:(UIScrollView *)scrollView 视图发生滚动时触发
• - (void)scrollViewDidZoom:(UIScrollView *)scrollView 视图发生放大触发
• - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView 视图开始拖动时候触发
• - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset 拖动结束触发
• - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate 减速时候触发，decelerate 表示减速后会继续减速。
• - (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView 手指抬起时
• - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView 视图停止滚动时候触发
• - (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView setContentOffset执行完后触发，如果没有动画则不触发。
• - (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(nullable UIView *)view 视图即将缩放时候触发
• - (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView 返回一个YES返回到顶部
• - (void)scrollViewDidScrollToTop:(UIScrollView *)scrollView 滚动动画时候触发，如果在顶部立即触发。