很多App中,新闻或者展示类都存在下拉刷新和上拉加载的效果,网上提供了实现这种效果的第三方类(详情请见MJRefresh和EGOTableViewPullRefresh),用起来很方便,但是闲暇之余,我们可以思考下,这种效果实现的原理是什么,我以前说过,只要是动画都是骗人的,只要不是硬件问题大部分效果都能在系统UI的基础上做出来.
@下面是关键代码分析:
- - (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
- {
- if (scrollView.contentOffset.y < - 100) {
-
- [UIView animateWithDuration:1.0 animations:^{
-
-
- self.tableView.contentInset = UIEdgeInsetsMake(150.0f, 0.0f, 0.0f, 0.0f);
- } completion:^(BOOL finished) {
-
-
-
- }];
- }
- }
-
- - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
- {
-
- NSLog(@"%f",scrollView.contentOffset.y);
- NSLog(@"%f",scrollView.frame.size.height);
- NSLog(@"%f",scrollView.contentSize.height);
-
- if (scrollView.contentOffset.y + scrollView.frame.size.height >= scrollView.contentSize.height) {
-
- NSLog(@"%d %s",__LINE__,__FUNCTION__);
- [UIView commitAnimations];
-
- [UIView animateWithDuration:1.0 animations:^{
-
- self.tableView.contentInset = UIEdgeInsetsMake(0, 0, 60, 0);
- } completion:^(BOOL finished) {
-
-
- }];
-
- }
- }
下拉刷新和上拉加载的原理
原文：http://www.cnblogs.com/-ios/p/4785366.html
