UITableview 上提刷新

/*TableViewController.m*/
//UIScrollViewDeleagete Methods
1 - (void)scrollViewDidScroll:(UIScrollView *)scrollView
2 {        
3     [footview RefreshScrollViewDidScroll:scrollView];//只要滑动就会触发，这时候要通知footview
4 }
5 
6 - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
7 {
8     [footview RefreshScrollViewDidEndDragging:scrollView];//滑动结束，通知footview    
9 }
//这段代码是tableview的控制器中，要实现通知footview滑动消息的两个委托方法。

//Footview.m
 1 //手指屏幕上不断拖动调用此方法
 2 - (void)RefreshScrollViewDidScroll:(UIScrollView *)scrollView {    
 3     
 4     if (_state == PullRefreshLoading) {//footview显示“正在加载”状态
 5         
 6         CGFloat offset = MAX(scrollView.contentOffset.y * -1, 0);
 7         offset = MIN(offset, 60);
 8         scrollView.contentInset = UIEdgeInsetsMake(0.0, 0.0f, RefreshViewHight, 0.0f);//将表格数据提上去，为footview腾出空间
 9         
10     } else if (scrollView.isDragging) {//拖动，但是没有松开，这个时候需要根据拖动的距离显示"上拉加载更多数据"或者“松开即可加载更多”
11         
12         BOOL _loading = NO;
13         if ([_delegate respondsToSelector:@selector(egoRefreshTableHeaderDataSourceIsLoading:)]) {
14             _loading = [_delegate RefreshTableHeaderDataSourceIsLoading:self];//从tableview获取是不是正在加载更多数据，如果是的话，那么footview将不做出反应，也就是说，保证每次只加载一次数据
15         }
16         
17         if (_state == EGOOPullRefreshPulling && scrollView.contentOffset.y + (scrollView.frame.size.height) < scrollView.contentSize.height + RefreshViewHight && scrollView.contentOffset.y > 0.0f && !_loading) {
18             [self setState:PullRefreshNormal];//footview显示"上拉将加载更多"
19         } else if (_state == EGOOPullRefreshNormal && scrollView.contentOffset.y + (scrollView.frame.size.height) > scrollView.contentSize.height + RefreshViewHight  && !_loading) {
20             [self setState:PullRefreshPulling];//footview显示"松开即加载更多"
21         }
22         
23         if (scrollView.contentInset.bottom != 0) {//将表格恢复，将看不到footview
24             scrollView.contentInset = UIEdgeInsetsZero;
25         }
26         
27     }
28     
29 }

32 //当用户停止拖动，并且手指从屏幕中拿开的的时候调用此方法
33 - (void)RefreshScrollViewDidEndDragging:(UIScrollView *)scrollView {
34     
35     BOOL _loading = NO;
36     if ([_delegate respondsToSelector:@selector(RefreshTableHeaderDataSourceIsLoading:)]) {
37         _loading = [_delegate RefreshTableHeaderDataSourceIsLoading:self];//询问tableview是否正在加载数据
38     }
39     //如果拖动的距离大于footview的高度，并且没有正在加载数据
40     if (scrollView.contentOffset.y + (scrollView.frame.size.height) > scrollView.contentSize.height + RefreshViewHight && !_loading) {
41         
42         if ([_delegate respondsToSelector:@selector(egoRefreshTableHeaderDidTriggerRefresh:)]) {
43             [_delegate RefreshTableHeaderDidTriggerRefresh:self];//通知tableview去加载更多数据
44         }
45         
46         [self setState:PullRefreshLoading];//footview状态更改为”正在加载“
47         [UIView beginAnimations:nil context:NULL];
48         [UIView setAnimationDuration:0.2];
49         scrollView.contentInset = UIEdgeInsetsMake(0.0f, 0.0f, RefreshViewHight, 0.0f);
50         [UIView commitAnimations];
51         
52     }
53 }　　　

//tableview.m 实现的footview要求的协议方法
 1 - (void)RefreshTableHeaderDidTriggerRefresh:(RefreshTableHeaderView*)view{
 2     
 3     [self reloadTableViewDataSource];//加载数据
 4     [self performSelector:@selector(doneLoadingTableViewData) withObject:nil afterDelay:4.0];//加载完毕
 5     
 6 }
 7 
 8 - (BOOL)RefreshTableHeaderDataSourceIsLoading:(RefreshTableHeaderView*)view{
 9     
10     return _reloading; // should return if data source model is reloading
11     
12 }

 1 - (void)reloadTableViewDataSource{
 2     
 3     //  在这里加载更多数据
 4     //  put here just for demo
 5     _reloading = YES;
 6     
 7 }
 8 
 9 - (void)doneLoadingTableViewData{
10     
11     //  model should call this when its done loading
12     _reloading = NO;
13     [_refreshHeaderView egoRefreshScrollViewDataSourceDidFinishedLoading:self.tableView];//加载完毕后通知footview
14     
15 }