コンテンツを正規表現phpに置き換えます

$rule = <span>"</span><span>/(?:\[)(f_.[0-9]{1,3})(?:\])/i</span><span>"</span>;

echo preg_replace(<span>"</span><span>/(?:\[)(f_.[0-9]{1,3})(?:\])/i</span><span>"</span>,<span>"</span><span><img src='__PUBLIC__/face/\${1}.png'></span><span>"</span>,$line[<span>'</span><span>content</span><span>'</span>]);

$line['content']   这个是我从数据库中取出的内容，

"<img src='__PUBLIC__/face/\${1}.png'>"  这个是我将要替换的图片地址,比如我的图片地址是这样的<img src="__PUBLIC__/face/f_013.png"><br>这里面有一个非常重要的知识点: "\${1}"   它就是那个存放在数据库里面表情的字符串。<br>\${1} = f_013 <br>我这里有我替换的一个完整代码:

<em><span><?php<br>$result</span> = <span>array</span><span>();
     </span><span>$n</span> = <span>preg_match_all</span>("/(?:\[)(f_.[0-9]{1,3})(?:\])/i",<span>$line</span>['content'], <span>$result</span><span>); /*返回查找到符合条件的字符串的个数*/
     </span><span>if</span>(<span>$n</span> == 0 || <span>$n</span> == <span>false</span><span>)   /*如果是0或者false就说明没有表情*/<br>　　　{
        </span><span>echo</span><span>$line</span>['content'<span>];
     }</span><span>else<br></span><span>　　　{
     　　</span><span>echo</span><span>preg_replace</span>("/(?:\[)(f_.[0-9]{1,3})(?:\])/i","<img src='__PUBLIC__/face/\${1}.png'>",<span>$line</span>['content'<span>]);
     }
     </span>?></em>