tableview设置上下滚动高度，启用删除

可在viewDidAppear中实现加入 ［tablvew setContentOffset:CGPointMake(0,480) animated:YES］； 
在tableView内添加一个searchbar，一起滚动；开始时隐藏headerView（即让tableView向上滚动headerView的高度：默认44） 
UISearchBar *mySearchBar = [[UISearchBar alloc] init]; 
[mySearchBar sizeToFit]; 
 
tableView.tableHeaderView = mySearchBar; 
//UITableView开始滚动到的位置（这样一开始headerView是不显示的） 
[tableView setContentOffset:CGPointMake(0.0, 44.0) animated:NO]; 


//启用删除
- (void)tableView:(UITableView*)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomAlarmCell *cell = (CustomAlarmCell*)[tableView cellForRowAtIndexPath:indexPath];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDelay:.1f];
    [UIView commitAnimations];
}

- (void)tableView:(UITableView*)tableView didEndEditingRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomAlarmCell *cell = (CustomAlarmCell*)[tableView cellForRowAtIndexPath:indexPath];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDelay:.1f];
    [UIView commitAnimations];
}