如何设置contentOffset：在insertRowAtIndexPath之后：

Question

I developing an app for iOS 5.

How I can set the contentOffset after a row is inserted ( insertRowAtIndexPath: ) in a table view? insertRowAtIndexPath: sets the offset to 0. I have tried to set the offset in willDisplayRow: delegate method but without result.

Answer 1

If the issue that you you want to change the offset after the row insertion animation has completed, then call a method to set the offset after delay. This will let the current run loop finish, allowing for the row insertion animation to complete. You may want to disable interaction with the table view during the delay.

You could try adding something like the following to your tableViewController.

- (void) adjustsContentOffset: (NSIndexPath*) indexPath;
{
    CGFloat offsetY = 0.0; // insert some calculation deriving your value from indexPath
    [[self tableView] setContentOffset: CGPointMake(0.0, offsetY) animated: YES];
}

- (void) insertRow: (NSIndexPath*) indexPath;
{
    [[self tableView] insertRowsAtIndexPaths: [NSArray arrayWithObject: indexPath] withRowAnimation:UITableViewRowAnimationLeft];
    [self performSelector: @selector(adjustsContentOffset:) withObject: indexPath afterDelay: 0.3];
}

Answer 2

Thanks Matthew again for your really helpful answer but finally I found another solution that i want to share with community:

Just add a empty cell at the end of a table with height that equals your desired offset