How to know the UITableview row number

Question

I have a UITableViewCell with UISwitch as accessoryview of each cell. When I change the value of the switch in a cell, how can I know in which row

Answer 1

If you set the tag property to the row number (as suggested by other answers), you have to update it every time in tableView:cellForRowAtIndexPath: (because a cell can be reused for different rows).

Instead, when you need the row number, you can walk up the superview chain from the UISwitch (or any other view) to the UITableViewCell, and then to the UITableView, and ask the table view for the index path of the cell:

static NSIndexPath *indexPathForView(UIView *view) {
    while (view && ![view isKindOfClass:[UITableViewCell class]])
        view = view.superview;
    if (!view)
        return nil;
    UITableViewCell *cell = (UITableViewCell *)view;
    while (view && ![view isKindOfClass:[UITableView class]])
        view = view.superview;
    if (!view)
        return nil;
    UITableView *tableView = (UITableView *)view;
    return [tableView indexPathForCell:cell];
}

This doesn't require anything in tableView:cellForRowAtIndexPath:.