Typecho 控制标题字数用省略号代替方法

<ul class="widget-navcontent">
				<li class="item item-01 active">
					<ul>
						<?php
						$this->widget('Widget_Contents_Post_Recent', 'pageSize=6')->to($recent);
						if ($recent->have()) :
							while ($recent->next()) :
						?>
								<li><time><?php $recent->date('Y-m-d'); ?></time><a href="<?php $recent->permalink(); ?>"><?php $recent->title(20, '...'); ?></a></li>
						<?php endwhile;
						endif; ?>
					</ul>