<?php /** * 通用的树型类，可以生成任何树型结构 */ class tree {     /**     * 生成树型结构所需要的2维数组     * @var array     */     var $arr = array();     /**     * 生成树型结构所需修饰符号，可以换成图片     * @var array     */     var $icon = array('│','├','└');     /**     * @access private     */     var $ret = '';     /**     * 构造函数，初始化类     * @param array 2维数组，例如：     * array(     *      1 => array('id'=>'1','parentid'=>0,'name'=>'一级栏目一'),     *      2 => array('id'=>'2','parentid'=>0,'name'=>'一级栏目二'),     *      3 => array('id'=>'3','parentid'=>1,'name'=>'二级栏目一'),     *      4 => array('id'=>'4','parentid'=>1,'name'=>'二级栏目二'),     *      5 => array('id'=>'5','parentid'=>2,'name'=>'二级栏目三'),     *      6 => array('id'=>'6','parentid'=>3,'name'=>'三级栏目一'),     *      7 => array('id'=>'7','parentid'=>3,'name'=>'三级栏目二')     *      )     */     function tree($arr=array())     {        $this->arr = $arr;        $this->ret = '';        return is_array($arr);     }     /**     * 得到父级数组     * @param int     * @return array     */     function get_parent($myid)     {         $newarr = array();         if(!isset($this->arr[$myid])) return false;         $pid = $this->arr[$myid]['parentid'];         $pid = $this->arr[$pid]['parentid'];         if(is_array($this->arr))         {             foreach($this->arr as $id => $a)             {                 if($a['parentid'] == $pid) $newarr[$id] = $a;             }         }         return $newarr;     }     /**     * 得到子级数组     * @param int     * @return array     */     function get_child($myid)     {         $a = $newarr = array();         if(is_array($this->arr))         {             foreach($this->arr as $id => $a)             {                 if($a['parentid'] == $myid) $newarr[$id] = $a;             }         }         return $newarr ? $newarr : false;     }     /**     * 得到当前位置数组     * @param int     * @return array     */     function get_pos($myid,&$newarr)     {         $a = array();         if(!isset($this->arr[$myid])) return false;         $newarr[] = $this->arr[$myid];         $pid = $this->arr[$myid]['parentid'];         if(isset($this->arr[$pid]))         {             $this->get_pos($pid,$newarr);         }         if(is_array($newarr))         {             krsort($newarr);             foreach($newarr as $v)             {                 $a[$v['id']] = $v;             }         }         return $a;     }       /**      * -------------------------------------      *  得到树型结构      * -------------------------------------      * @author  Midnight(杨云洲),  yangyunzhou@foxmail.com      * @param $myid 表示获得这个ID下的所有子级      * @param $str 生成树形结构基本代码, 例如: "<option value=\$id \$select>\$spacer\$name</option>"      * @param $sid 被选中的ID, 比如在做树形下拉框的时候需要用到      * @param $adds      * @param $str_group      * @return unknown_type      */     function get_tree($myid, $str, $sid = 0, $adds = '', $str_group = '')     {         $number=1;         $child = $this->get_child($myid);         if(is_array($child))         {             $total = count($child);             foreach($child as $id=>$a)             {                 $j=$k='';                 if($number==$total)                 {                     $j .= $this->icon[2];                 }                 else                 {                     $j .= $this->icon[1];                     $k = $adds ? $this->icon[0] : '';                 }                 $spacer = $adds ? $adds.$j : '';                 $selected = $id==$sid ? 'selected' : '';                 @extract($a);                 $parentid == 0 && $str_group ? eval("\$nstr = \"$str_group\";") : eval("\$nstr = \"$str\";");                 $this->ret .= $nstr;                 $this->get_tree($id, $str, $sid, $adds.$k.' ',$str_group);                 $number++;             }         }         return $this->ret;     }     /**     * 同上一方法类似,但允许多选     */     function get_tree_multi($myid, $str, $sid = 0, $adds = '')     {         $number=1;         $child = $this->get_child($myid);         if(is_array($child))         {             $total = count($child);             foreach($child as $id=>$a)             {                 $j=$k='';                 if($number==$total)                 {                     $j .= $this->icon[2];                 }                 else                 {                     $j .= $this->icon[1];                     $k = $adds ? $this->icon[0] : '';                 }                 $spacer = $adds ? $adds.$j : '';                 $selected = $this->have($sid,$id) ? 'selected' : '';                 //echo $sid.'=>'.$id.' : '.$selected.' . <br/>';                 @extract($a);                 eval("\$nstr = \"$str\";");                 $this->ret .= $nstr;                 $this->get_tree_multi($id, $str, $sid, $adds.$k.' ');                 $number++;             }         }         return $this->ret;     }     function have($list,$item){         return(strpos(',,'.$list.',',','.$item.','));     } } ?>