<?php if ($imgurls) {$key=0; foreach ($imgurls as $c) { ?>

  <a data-slide-index="{$key+1}" href="{dr_get_file($c.file)}" ><img src="{dr_get_file($c.file)}" alt="" /></a>

  <?php } } ?>

我这个代码为啥没有递增效果 

<a data-slide-index="1" href="http://szkmpc.com/uploads/allimg/200313/2-200313105H6.jpg" ><img src="http://szkmpc.com/uploads/allimg/200313/2-200313105H6.jpg" alt="" /></a>    
<a data-slide-index="1" href="http://szkmpc.com/uploads/allimg/200313/2-200313105H8.jpg" ><img src="http://szkmpc.com/uploads/allimg/200313/2-200313105H8.jpg" alt="" /></a>    
<a data-slide-index="1" href="http://szkmpc.com/uploads/allimg/200313/2-200313105I0.jpg" ><img src="http://szkmpc.com/uploads/allimg/200313/2-200313105I0.jpg" alt="" /></a>

输出的全是1