织梦如何在dede:channel 调用{dede:field.seotitle /}

网上很多人说 dede:channel 调用{dede:field.seotitle /}
 
只要把{dede:field.seotitle /}改成[field:seotitle/] 就行了
 
可是自己试了下还是不行.
 
最后才发现原来要在include\taglib\channel.lib.php   
 
找到下面黑色代码,加入下面红色代码 seotitle,即可
 
位置在78行
 
 if($type=='top')
    {
        $sql = "SELECT id,typename,seotitle,typedir,isdefault,ispart,defaultname,namerule2,moresite,siteurl,sitepath
          From `dede_arctype` WHERE reid=0 And ishidden<>1 order by sortrank asc limit 0, $line ";
    }
    else if($type=='son')
    {
        if($typeid==0) return '';
        $sql = "SELECT id,typename,seotitle,typedir,isdefault,ispart,defaultname,namerule2,moresite,siteurl,sitepath
          From `dede_arctype` WHERE reid='$typeid' And ishidden<>1 order by sortrank asc limit 0, $line ";
    }
    else if($type=='self')
    {
        if($reid==0) return '';
        $sql = "SELECT id,typename,seotitle,typedir,isdefault,ispart,defaultname,namerule2,moresite,siteurl,sitepath
            FROM `dede_arctype` WHERE reid='$reid' And ishidden<>1 order by sortrank asc limit 0, $line ";
    }