ios 下拉刷新

ios应用里需要用到下拉刷新来更新应用的数据，ios自带的下拉刷新UIRefreshControl目前只能用于UITableViewController

-(void)beginRefreshing //创建下拉刷新
{
    refresh = [[UIRefreshControl alloc]init];
    refresh.tintColor = [UIColor lightGrayColor];
    refresh.attributedTitle = [[NSAttributedString alloc]initWithString:@"下拉刷新"]; //属性名称为下拉刷新
    [refresh addTarget:self action:@selector(refreshTabelviewAction:) forControlEvents:UIControlEventValueChanged]; //添加事件
    self.refreshControl = refresh;
    
}
-(void)refreshTabelviewAction:(UIRefreshControl *)refreshs
{
    if(refreshs.refreshing)//正在刷新的时候的显示
    {
        refreshs.attributedTitle = [[NSAttributedString alloc]initWithString:@"正在刷新"];
        [self performSelector:@selector(refreshData) withObject:nil afterDelay:2];
    }
}
-(void)refreshData
{
    NSString *syseTime = nil;
    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
    [formatter setDateFormat:@"yyyy-mm-dd hh:mm:ss" ];
    syseTime = [formatter stringFromDate:[NSDate date]];
    NSString *lastUpdated = [NSString stringWithFormat:@"上一次更新时间为 %@", [formatter stringFromDate:[NSDate date]]];
    self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:lastUpdated] ;//以上为刷新时显示上一次刷新的时间
    [self.refreshControl endRefreshing];//结束刷新
    [self.tableView reloadData];//重新加载数据
    
}