如何在tableview上实现循环滚动。

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return numberOfActualRows*100;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSUInteger actualRow = indexPath.row % numberOfActualRows;
    ...
}

self.tableView.showsVerticalScrollIndicator = NO;

[self.tableView scrollToRowAtIndexPath: [NSIndexPath indexPathForRow:[self tableView:self.tableView numberOfRowsInSection:0]/2 inSection:0]  atScrollPosition:UITableViewScrollPositionTop animated:NO];

/* To emulate infinite scrolling...

The table data was doubled to join the head and tail: (suppose table had 1,2,3,4)
1 2 3 4|1 2 3 4 (actual data doubled)
---------------
1 2 3 4 5 6 7 8 (visualising joined table in eight parts)

When the user scrolls backwards to 1/8th of the joined table, user is actually at the 1/4th of actual data, so we scroll instantly (we take user) to the 5/8th of the joined table where the cells are exactly the same.

Similarly, when user scrolls to 6/8th of the table, we will scroll back to 2/8th where the cells are same. (I\'m using 6/8th when 7/8th sound more logical because 6/8th is good for small tables.)

In simple words, when user reaches 1/4th of the first half of table, we scroll to 1/4th of the second half, when he reaches 2/4th of the second half of table, we scroll to the 2/4 of first half. This is done simply by subtracting OR adding half the length of the new/joined table.

 Written and posted by Anup Kattel. Feel free to use this code. Please keep these comments if you don\'t mind.
*/


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

    CGFloat currentOffsetX = scrollView_.contentOffset.x;
    CGFloat currentOffSetY = scrollView_.contentOffset.y;
    CGFloat contentHeight = scrollView_.contentSize.height;

    if (currentOffSetY < (contentHeight / 8.0)) {
    scrollView_.contentOffset = CGPointMake(currentOffsetX,(currentOffSetY + (contentHeight/2)));
    }
   if (currentOffSetY > ((contentHeight * 6)/ 8.0)) {
       scrollView_.contentOffset = CGPointMake(currentOffsetX,(currentOffSetY - (contentHeight/2)));
    }

}