#import "ViewController.h"

@interface ViewController ()<UIScrollViewDelegate>{

    UIView * _loadView;

}

- (void)viewDidLoad {

    _loadView = [[UIView alloc] initWithFrame:CGRectMake(,  -, , )];

    //...

}

#pragam mark UIScrollView Delegate

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {

    _loadView.frame = CGRectMake(, - - scrollView.contentOffset.y, , );

    if (scrollView.contentOffset.y<= -) {

        //处理松开刷新提示

    }  else {

        //关闭松开刷新提示

    }

}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {

    if (scrollView.contentOffset.y<= -) {

        //此处动画纯粹为了过度平滑

        [UIView animateWithDuration:0.2 animations:^(void) {

             scrollView.contentInset = UIEdgeInsetsMake(, , , );

         }completion:^(BOOL complete) {

             //处理需要加载的东西

        }];

    }

}

//...