//contentSize、contentInset和contentOffset 是 scrollView三个基本的属性。 // 滚动self.ScrollView.contentSize =self.imageview.frame.size;//偏移X =0  Y  =-74 向下偏移self.ScrollView.contentOffset =CGPointMake(0,-74);// 边距 距离顶部74 左 0  下40 右0self.ScrollView.contentInset = UIEdgeInsetsMake(74, 0, 40, 0); //不显示水平滚动条    self.ScrollView.showsHorizontalScrollIndicator =NO; //不显示垂直滚动条    self.ScrollView.showsVerticalScrollIndicator =NO;//控制器 实现 UIScrollViewDelegate 代理    @interface ViewController () 
     
      //只要滚动了就会触发- (void)scrollViewDidScroll:(UIScrollView *)scrollView;   {//    NSLog(@" scrollViewDidScroll");    NSLog(@"ContentOffset  x is  %f,yis %f",scrollView.contentOffset.x,scrollView.contentOffset.y);}//开始拖拽视图- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView;   {   NSLog(@"scrollViewWillBeginDragging");}//完成拖拽- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate; {   NSLog(@"scrollViewDidEndDragging");}//将开始降速时- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView;   {   NSLog(@"scrollViewWillBeginDecelerating");}//减速停止了时执行，手触摸时执行执行- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView;   {   NSLog(@"scrollViewDidEndDecelerating");}//滚动动画停止时执行,代码改变时出发,也就是setContentOffset改变时- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView;{   NSLog(@"scrollViewDidEndScrollingAnimation");}//设置放大缩小的视图，要是uiscrollview的subview- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView;   {    //返回要缩放的子控件，每次只能缩放一个子控件    return imageView;}//完成放大缩小时调用- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale; {      NSLog(@"完成放大缩小时调用");}//如果你不是完全滚动到滚轴视图的顶部，你可以轻点状态栏，那个可视的滚轴视图会一直滚动到顶部，那是默认行为，你可以通过该方法返回NO来关闭它- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView;   {    NSLog(@"scrollViewShouldScrollToTop");   return YES;}- (void)scrollViewDidScrollToTop:(UIScrollView *)scrollView;     {    NSLog(@"scrollViewDidScrollToTop");}-(void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view{    NSLog(@"用户开始缩放时调用！！scrollViewWillBeginZooming");}-(void)scrollViewDidZoom:(UIScrollView *)scrollView{    NSLog(@"用户正在缩放调用！scrollViewDidZoom");}