UIScrollView

UIScrollView

• 一般会使用到的

1.  scrollView = [[UIScrollView alloc]
2.      initWithFrame:CGRectMake(0, 20, self.view.bounds.size.width,
3.                               self.view.bounds.size.height - 20)];
4.
5.  scrollView.contentSize = size;// 内容大小
6.  scrollView.showsHorizontalScrollIndicator = NO;// 是否显示水平滚动指示器
7.  scrollView.showsVerticalScrollIndicator = NO; // 是否显示垂直滚动指示器
8.  scrollView.bounces = YES; // 是否提供弹簧状态
9.  scrollView.pagingEnabled = NO; // 是否分页
10.  scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite; //设置滚动条颜色
11.  scrollView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 20, 20); //设置滚动条位置对边界的偏移值
12.  scrollView.decelerationRate = 1; // 滚动条减速的效果 1 和 1000效果差不多
13.  scrollView.scrollsToTop = NO; // NO 不允许点击状态栏回到顶部
14.
15.  [scrollView addSubview:imageView];
16.
17.  [self.view addSubview:scrollView];

• scrollView还能实现图片缩放,缩放不能显示水平和垂直滚动指示器

1.//  委托 实现缩放
2.  scrollView.delegate = self;
3.  scrollView.maximumZoomScale = 5.0;
4.  scrollView.minimumZoomScale = 0.1;

代理需要实现方法,返回需要缩放的view

1.// 缩放回调
2.- (UIView *)viewForZoomingInScrollView:(UIScrollView *)_scrollView {
3.  return [_scrollView.subviews lastObject];
4.}

---

• 若需要对scrollView滚动或者缩放过程中／后做一些事情，那么需要放在代理中实现

1.
2.@protocol UIScrollViewDelegate<NSObject>
3.
4.@optional
5.
6.- (void)scrollViewDidScroll:(UIScrollView *)scrollView; 
7.
8.- (void)scrollViewDidZoom:(UIScrollView *)scrollView NS_AVAILABLE_IOS(3_2); 
9.
10.- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView;
11.
12.- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset NS_AVAILABLE_IOS(5_0);
13.
14.- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate;
15.
16.- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView;   
17.
18.- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView;      
19.
20.- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView; 
21.
22.- (nullable UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView;     
23.
24.- (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(nullable UIView *)view NS_AVAILABLE_IOS(3_2); 
25.
26.- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(nullable UIView *)view atScale:(CGFloat)scale; 
27.
28.- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView;   
29.
30.- (void)scrollViewDidScrollToTop:(UIScrollView *)scrollView;      
31.
32.@end
33.
34.