iOS UITableView滑动到底部

- (void)scrollToBottom:(BOOL)animate{
    if (!self.isScroll) return;
    self.isScroll = NO;
    NSInteger numberOfSections = [self.datasource numberOfSections];
    NSInteger numberOfRows = [self.datasource numberOfRowsInSection:(numberOfSections-1)];
    if (!numberOfSections) {
        return;
    }
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:(numberOfRows - 1) inSection:(numberOfSections - 1)];
    dispatch_async(dispatch_get_main_queue(), ^{
        if (indexPath.section < self.datasource.numberOfSections && indexPath.row < [self.datasource numberOfRowsInSection:indexPath.section]) {
            [self.tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionBottom animated:animate];
        }
    });
}

以上代码之前滑动到底部还可以，最近发现滑不到最底部。

解决办法：

_tableView.estimatedRowHeight = 0;
_tableView.estimatedSectionFooterHeight = 0;
_tableView.estimatedSectionHeaderHeight = 0;