通过点击cell上的Button获取tableView的indexPath

- (void)buttonClickedWith:(UIButton *)button event:(UIEvent *)event
{
    NSSet *touches =[event allTouches];
    UITouch *touch =[touches anyObject];
    CGPoint point = [touch locationInView:mainTableView];
    NSIndexPath *indexPath= [mainTableView indexPathForRowAtPoint:point];
}